How to Install Black, Red & White Wires in a Light Switch
- 1). Locate and turn off the circuit breaker that supplies electricity to the switch.
- 2). Pull the red, white and black wires out of the wall so that they can be tested without touching them. Turn on the circuit breaker so the wires can be tested.
- 3). Place one probe of a voltage meter on the bare part of the white wire and touch the other probe to the bare part of each of the other two wires in turn. Whichever wire lights up the voltage meter is the hot; the other is the ground.
- 4). Turn off the circuit breaker. Connect the hot wire to the brass screw on the switch. Connect the white wire to the silver screw. Connect the ground wire to the greenish screw.
- 5). Reassemble the switch and switch plate and turn on the circuit breaker.