How to Wire a Light Switch to 2 Lights

If you have certain lights that you always use in tandem (like your porch light and garage light, for instance), it can be to your advantage to wire a light switch to both lights, so that you don’t have to turn each of them on individually. Naturally, wiring to lights to one light switch is a little bit more complicated than your standard light switch wiring job, but with a little foreknowledge and prep time this is a job that the wiring-savvy do-it-yourselfer can do him or herself. Keep reading for some useful guidelines.

Step 1 - Cut the Juice

As with any wiring job, the very first step is to turn off the power. Go to your circuit breaker box or service panel and cut the juice to the circuit that you will be working on. Use your voltage tester to ensure that there is no power in any of the wires; check in the service panel, and then unscrew the switch cover (if there is already a switch) and check the wires there. If your tester lights up or buzzes, then there is still current in the wires.

Step 2 - Connect the White and Black Wires

Follow these instructions if the power supply for the lights is connected to the first light, as opposed to the light switch. If the power supply will be connected to the switch, skip to Step 4. Otherwise, you want to connect the light’s white wire with the power supply’s black wire by taking your wire strippers, removing a bit of the insulation, revealing the copper wires within and winding them together. Then, connect the power supply’s black wire with the switch’s white wire. This wire is going to be hot, so wrap it with a piece of electrical tape so that you can identify it.

Step 3 - Run the Cable Between the Lights

Run the cable in between the first and second lights. Take the switch’s black wire. Connect it to the first light’s black wire and the second light’s black wire. Take the power’s supply white wire and connect it to the second light’s white wire.

Step 4 - Connecting the Power Supply to the Switch

If the power supply for the lights is connected directly to the switch, as opposed to the first light, then you should have gone directly from Step 1 to this step. Simply take the power supply’s black wire and white wire, and connect them to the switch’s wires, connecting like to like. Connect the black wire from the switch to the black wire from the first light. Connect the black and white wires (again, connecting like to like) between the first and second lights.

Step 5 - Connect the Rest of the Wires

There should be some bare wires and some green wires left over. Connect them together, like to like. Connect green screws on the lights and switches to the bare wires. At any place where wires have been connected, attach a wire connector.