How to Replace a Light Switch

Safety First — Isolate the Circuit

Before touching any electrical fitting, turn off the circuit at the consumer unit. Switch off the lighting circuit breaker for the room you are working in. Use a non-contact voltage tester to verify no power is present before touching any wires.

What You Will Need

A flat-head and Phillips screwdriver, a non-contact voltage tester, the replacement switch (match the number of gang), and electrical tape. No specialist tools required.

Step 1 — Remove the Old Switch

Unscrew the two screws on the switch faceplate and carefully pull it away from the wall. Note which wire connects to which terminal before disconnecting anything. Take a photo with your phone for reference.

Step 2 — Identify the Wiring

In older properties you may see red and black wires. In newer properties, brown (live) and blue (neutral) with a green and yellow earth. The switch only interrupts the live switched live wire.

Step 3 — Connect the New Switch

Connect the wires to the same terminals on the new switch as they were on the old one. Tighten the terminal screws firmly. The earth wire connects to the earth terminal on the metal back box if present.

Step 4 — Fit and Test

Carefully fold the wires back into the back box and screw the new faceplate in place. Restore power at the consumer unit and test the switch. If it works correctly, the job is done.