Replace a light switch
Save £60–100 today
30 mins · Beginner · Saves £60–100 vs an electrician
Last updated: March 2025
Before you start
Replacing a light switch is one of the safest electrical jobs at home. Light switches carry low current, and the work is entirely at the switch — not at the consumer unit.
The critical rule: always turn off the power at the consumer unit before touching any wiring. Not just the switch itself — the actual circuit breaker.
Tools needed
- ✓Flat-head screwdriver — to open terminal screws
- ✓Cross-head screwdriver — to remove the face plate
- ✓Phone camera — photograph the wiring before disconnecting anything
- ✓Pipe & cable detector — to confirm no cables in the wall before any drilling
- !Replacement switch — buy: buy: £5–15 — standard 1-gang or 2-gang white plate from any hardware shop
Turn off the power at the consumer unit
Find the lighting circuit breaker for this room in your consumer unit and switch it off. Test the light confirms the power is off.
Where beginners go wrong
Not turning off the power at the consumer unit — turning off the switch is not enough. The live wire is still live.
Reconnecting wires to the wrong terminals — always use your photo as a reference.
Overtightening the face plate screws — this cracks the plastic. Finger-tight plus a quarter-turn is enough.
Stop and call a electrician if...
You find more than 3 wires at the switch — this may be two-way switching or loop wiring
There is any burning smell or discolouration on the existing wiring
You are not confident after seeing the wiring — there is no shame in stopping
Cost breakdown
What you just learned
You now understand how a single-gang light switch is wired and how to safely isolate a circuit. This transfers to replacing plug sockets and fitting dimmer switches.
✅ Completed by 3,028 people
⚠️ Watch out if you rent
Like-for-like switch replacement is generally acceptable, but always get your landlord's written agreement before doing any electrical work in a rented property. Keep a record of what you did.