It is the responsibility of the user of this information to know and understand the NEC (National Electrical Code) as it applies to them, as well as any local regulations or laws that may pertain. While many jurisdictions do adopt the standards of the NEC, some may have requirements in addition to, or exemptions from those standards. The information on this page is intended to aid in electrical wiring projects that become necessary when doing DIY home improvements and repairs. We cannot assume responsibility for personal injury or property damage as a result of using the information provided here.
Note: Some of these wiring arrangements may be found in existing circuits you will encounter while doing home improvement projects. Because the NEC code is updated every 3 years, not all of these diagrams will adhere to the latest changes, but are still useful for identifying circuits you must deal with when disconnecting old switches, lighting fixtures or receptacle outlets.
If you are running new circuits, check for the "UPDATED DIAGRAM" notation in the drawing or check the most recent code changes to be sure any new wiring you run is done according to the latest requirements.
This page contains wiring diagrams for household light switches and includes a switch loop, a single-pole switch, rheostat dimmer and a few choices for wiring a combo receptacle/switch device. Also included are wiring arrangements for multiple light fixtures and a split receptacle controlled by two switches.
In the diagrams on this website the brass colored terminals on the devices represent the hot side of the circuit and the silver colored terminals represent the neutral side. Green is used to denote ground wires and terminals. Not all outlet boxes or older devices will have a grounding terminal. When running new wiring the ground wires should be spliced with a short piece of wire to connect to each device that has a grounding terminal, and to any grounding terminals in the outlet boxes. Also be aware that the white wire may be use to carry current in some household circuits, in these cases it should be marked with black electrical tape to indicate it is hot.
When the electrical source originates at a light fixture and it's controlled from a remote location, a switch loop is used. The circuit pictured here is wired with 2-conductor cable running from the light to the switch location. The white cable wire in this switch loop is wrapped with black tape and connected to the bottom terminal on SW1, the black wire is connected to the top terminal. At the light the black wire connects to the hot terminal. The neutral from the source is connected directly to the neutral terminal on the light.
Below is an updated version of the switch loop arrangement. Because the electrical code as of the 2011 NEC update requires a neutral wire in all switch boxes, it is spliced at the fixture and run through to the switch box using 3 conductor cable.
Here a single-pole switch controls the electricity to a light fixture. The source is at the switch and 2-conductor cable runs from there to the light. The source hot wire is connected to the bottom terminal on the switch and the top terminal is connected to the black cable wire. The neutral wire from the source is spliced to the white cable wire and continues on to the light, it doesn't connect to the SW1 at all. At the light, the white wire connects to the neutral terminal and the black wire connects to the hot.
Here two switches are wired in the same box to control two separate light fixtures. The source is at the switch box and a 2-conductor cable is run to each light. The source hot is spliced to each switch with a pigtail to power the lights.
This diagram illustrates wiring for more than one light fixture controlled by the same switch. The source is at SW1 and 2-conductor cable runs from there to the fixtures. The hot and neutral terminals on each fixture are spliced with a pigtail to the circuit wires which then continue on to the next light. This is the simplest arrangement for more than one light on a single switch.
A rheostat, or dimmer, makes it possible to vary the current flowing to a light fixture thereby varying the intensity of the light. The dimmer will have stranded wires that must be sliced to the solid cable wiring with a pigtail. A device like this should only be used with a light fixture and not with a ceiling fan or other motor. See wiring a speed controller for more about rheostats to control fan speed.
To wire this circuit 2-conductor cable runs from the dimmer to the light. The source is at the dimmer and the hot wire is spliced to the input wire on the device. The output from the dimmer is spliced to the black cable wire which runs on to the hot terminal on the light. The neutral wire is spliced to the white cable wire which continues on to the neutral terminal on the light.
Here a receptacle outlet is controlled with a single-pole switch. This is commonly used to turn a table lamp on and off when entering a room. In this diagram 2-condutor cable runs between SW1 and the outlet. The source is at SW1 and the hot wire is connected to the bottom terminal there. The top terminal is connected to the black cable wire running to the hot terminal on the receptacle and the source neutral is spliced with the white cable wire which runs on to the neutral on the receptacle.
This diagram illustrates a switch and receptacle in the same outlet box and tapping the same source. This wiring allows the power to continue from the receptacle, on to any other outlets in the circuit, and it provides a switch to control a light fixture or other load such as another receptacle or a fan.
This diagram illustrates the wiring for a split receptacle with one half controlled by SW1 and the other half always hot. The receptacle is split by breaking the connecting tab between the two, brass colored terminals. The tab between the neutral, silver terminals should remain intact. Here the source is at the receptacle and 2-conductor cable runs from there to SW1. The hot source is spliced to a pigtail that connect to the bottom, always-hot half on the receptacle and to the white cable wire which continues on to the bottom terminal on SW1. The black cable wire is connected to the top terminal on SW1 and runs to the top, hot terminal on the receptacle. The circuit neutral wire is connected to one of the neutral terminals on the receptacle, it doesn't run to SW1 at all.
In the updated diagram below 3-conductor cable runs between the receptacle and switch, and the red cable wire is used to carry the hot source to the bottom terminal on the switch. The neutral from the source is passed through to the switch box using the white wire and in this diagram the white wire is capped with a wire nut. This represents a change in the NEC code that requires a neutral wire in all switch boxes to accommodate new smart switches that can be programed to control lights and other loads. If you are running a new circuit check the electrical code to understand this and any other updates to the required procedure.
In this circuit a split receptacle is controlled by two single-pole switches. With this arrangement two lamps can be plugged into the same receptacle and each can be controlled separately, from two locations.
Here again, the connecting tab between the receptacle terminals is broken off and the neutral tab remains intact. The source is at SW1 and 3-conductor cable runs from there to the receptacle, 2-conductor cable runs from the receptacle to SW2. The source hot wire is splice to the bottom terminal on SW1 and to the red cable. The top terminal is connected to the black cable wire and the source neutral wire is spliced to the white wire which continues on to one of the neutral terminals on the receptacle, it doesn't matter which, only one connection is needed with the neutral wire.
At the receptacle the black cable wire from SW1 is connected to one of the hot terminals and the red wire is spliced to the white wire on the 2-conductor cable running to SW2. The white wire is wrapped with electrical tape to mark it as hot. The black wire is connected to the second hot terminal on the receptacle and to the top terminal on SW2.
In the updated diagram below 3-conductor cable runs between the receptacle and SW2 to allow for splicing the neutral source through to the second switch box. Here the white is not used for hot but instead the extra, red wire serves that purpose for the second switch.
A combo switch/receptacle is handy when you need both, but you only have one outlet box available. Like the split receptacles above these devices makes use of a removable connector between the two, hot terminals to divide the device when needed. When intact and wired to one hot source wire, the combo device can be used to turn a light off and on, while the receptacle will be constantly hot.
This diagram shows the first wiring option for this device. In this arrangement the connecting tab between the hot terminals remains intact. The hot source is at the device and the black wire is connected directly to one of the hot terminals, it doesn't matter which one. From there 14/2 cable runs to a light fixture and the black wire is connected at the combo device to the silver, neutral side of the switch half. At the other end it is connected to the hot terminal on the load. The source neutral wire is spliced to the neutral on the receptacle half of the combo device and to the white 14/2 wire going to the load, where it is connected to the neutral terminal on the fixture.
This is another option for wiring a combo device where two sources are used for two different loads. In this drawing the connecting tab between the hot terminals on the device is broken off. With this arrangement the switch controls a light and the receptacle half of the combo device is constantly hot.
Source 1 comes in at the light fixture and a 14/2 cable is run from there to the switch half on the device. The hot from the source is spliced to the black 14/2 wire and to the input side of the switch at the other end. The white wire from the source is connected directly to the light fixture. The white 14/2 wire is wrapped with black tape and connected to the hot terminal on the fixture and to the output side of the switch at the other end. The 14/2 ground wire is not used on this cable and should be taped and folded to the back of the outlet box.
Source 2 comes in at the combo where the hot and neutral wires are connected to their corresponding terminals on the receptacle half of the device.
Here the receptacle outlet half of the device is controlled with the built-in switch. This may be a convenient arrangement if you want to use the device to control a load plugged into the receptacle.
In this diagram the tab between the hot terminals is broken off and a short, jumper wire is run from the output side of the switch to the input or hot terminal on the receptacle. The hot source wire is connected to the input side of the switch and the source neutral wire is connected to the neutral terminal on the receptacle.