Wiring Diagrams for Household Switches

This page contains wiring diagrams for household light switches. These can be used to control lights or receptacle outlets, or both in the same circuit. Diagrams on this page include a switch loop, single–pole switch, rheostat dimmer, a combo device as well as wiring for multiple light fixtures.

Note: These drawing illustrate 15 amp circuits using 14 awg cable, when using these diagrams for 20 amp circuits, 12 gauge wire and 20 amp devices should be used instead. When using a white wire to carry current in these circuits it should be marked with black electrical tape so anyone working on the wiring in the future knows it may be hot. Ground wires should be spliced with a short piece of wire to connect to each device that has a grounding terminal. If the outlet box has a grounding terminal the wire should be connected there too.

When the electrical source originates at a light fixture or a receptacle, a switch loop can be added to control the power to that device from a wall switch. To wired this circuit 14/2 awg is run from the fixture or receptacle, to the switch location.

The white cable wire is wrapped with tape and spliced to the hot source wire at the fixture box. At the switch the white wire is connected to the bottom terminal and the black wire connects to the top terminal. At the fixture or receptacle the black wire is connected to the hot terminal. The white wire from the source is connected to the neutral terminal on the light or receptacle.

Here a single–pole switch controls the electricity to a light fixture. The source is at the switch and 14/2 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. At the light, the white wire connects to the neutral terminal and the black wire connects to the hot.

Wiring a Switch to Two or More Light Fixtures

This diagram illustrates wiring for more than one light fixture controlled by one switch. The source is at the switch and 14/2 cable runs from there to the fixtures. Two or more lights can be included and connected together with a pigtail to splice each wire to the fixture and to the cable running to the next light.

A rheostat or dimmer makes it possible to vary the current flowing to a light fixture, thereby varying the intensity of the light. This device will have stranded wires that must be sliced to the household wiring with a pigtail and capped with a wire nut. A dimmer 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 a ceiling fan.

To wire this circuit 14/2 cable runs from the dimmer to the light. The source hot wire is spliced to one of the black wires on the dimmer, it shouldn't matter which one as long as you use one of the same (usually black) colored wires. The other black wire is spliced to the black cable wire. At the switch box, the source neutral wire is spliced to the white cable wire. At the light the black goes to the hot terminal and the white to the neutral terminal.

Wiring a Switch to Control a Wall Receptacle

A single–pole, as well as 3 way and 4 way switches, can be used to control one or more wall receptacles. This is handy for turning a table lamp on and off when entering a room.

In this diagram 14/2 cable runs between the switch and the receptacle. The source is at the switch and the hot connects to the bottom terminal. The top terminal is connected to the black cable wire. The source neutral is spliced with the white cable wire. At the receptacle the black is connected to the hot terminal and the white to the neutral terminal.

Controlling a Split Receptacle

This diagram illustrates the wiring for a split receptacle with one half controlled by a wall switch and the other half always hot. The receptacle is split by breaking the connection between the two brass colored, hot terminals.

The source is at the outlet and 14/2 cable runs from there to the switch. The hot source is spliced to the bottom half of the receptacle and the bottom terminal on the switch. The top terminal is connected to the top half of the receptacle

Two Switches Control a Split Receptacle

In this circuit a split receptacle is controlled by two single-pole switches. With this arrangement two lamps can be plugged into the receptacle and each controlled separately from two locations.

Here the source is at one of the switches and 14/3 cable is run from there to the receptacle, 14/2 cable is run from the receptacle on to the second switch. The source hot wire is splice to the bottom terminal on the first switch and the red wire from the 14/3 cable. The top terminal is connected to the black cable wire and the source neutral is spliced with the white cable wire.

At the receptacle the black wire is connected to one of the hot terminals and the white wire to one of the neutral terminals, it doesn't matter which, only one connection is needed with the neutral wire. The red wire is spliced to the black wire on the 14/2 cable running to the second switch. The white wire from the 14/2 cable is wrapped with electrical tape and connected to the second hot terminal on the receptacle. At the second switch the black wire is connected to the bottom terminal and the white wire connected to the top terminal.

Wiring for a Combo Switch

A combo switch/receptacle is handy when you need both, but you only have one outlet box available. These devices come with a removable connector between the two hot terminals. When intact and wired to one hot source wire, this 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. Here the hot source comes in to the hot terminal on the receptacle and 14/2 cable runs from the device box to a light fixture. The source neutral is spliced to the receptacle and to the white cable wire going to the fixture. The output side of the switch is connected to the black cable wire running to the hot terminal on the fixture.

In this drawing the connection tab between the hot terminals on the device is broken off allowing for wiring two separate sources, one for the light and one for the receptacle. With this arrangement the switch controls a light and the receptacle outlet is constantly hot.

Source 1 comes in at the light fixture and a 14/2 loop runs to the switch half on the device. The hot from the source is spliced to the black wire on the loop and the source neutral connects directly to the fixture. At the combo device the black wire from the loop is connected to the input and the white wire is connected to the output. The cable ground wire is not used and should be taped and folded to the back of the boxes, out of the way.

Source 2 comes in at the device box where the hot and neutral wires are connected to the 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.