Changing a wall light switch

I just went to turn on the light in my lounge and the switch started sizzling. So tomorrow I intend to buy another switch and have a go at wiring it in. I’m totally useless at everything electrical - can anyone direct me to some idiot instructions please?

The current switch is a double but actually only works for one light (no idea about another light), so I thought I’d just buy a one switch switch!

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might not be as easy as you think , our double needed changing and after several attempts we had to get a electrician friend in to do it .

I’ve just remembered that I have an old DIY book here and it has some blurb on changing wall switches, even a two-way switch wired for one light!
However - it says to turn off the power and remove the fuse before taking off the face plate. Are they talking about taking the circuit breaker out of the main fuse box?

ours was a double dimmer we were changing back to a plain double , the set up and coloured wires were differant …

yes we isolated the down stairs wiring by flicking the circuit breaker in fuse box off

Lighting circuits can be quite complicated, and if you don’t even know which switch to buy (as there is a lot more to it than 1 2 or 3 actual switches), then get an electrician to do it. Damned dangerous stuff for the novice and saving a few quid certainly isn’t worth burning the house down for… :shock:

I agree with this wish we had the electrician in , in the first instance .

Hmmm - I do understand the sentiment, but it could take days and days to get an electrician in and it’s something I’d like to see if I can do. If I don’t succeed straight away, I’ll call half a dozen electricians and hope one turns up!

With lighting, it’s difficult to advise, unless you have owned the house from the start, you don’t know if someone else has had a go at it.

Do NOT do it yourself.

It could be quite simple, depending on the way it is wired at the moment.

To be safe, switch off the circuit breaker (no need to take it out!) or, better still, switch off the main switch and make sure there is no power at all in the house.

Then unscrew the light switch and take a clear photograph of what’s behind, specifically the back of the switch with wires attached of course.

Post it here, and if it looks correctly wired, I can probably help.

Changing a correctly wired light switch is simple, but if you are at all uncertain get in an electrician. It will probably be a quick and cheap job.

BTW, the switch ‘sizzling’ probably indicates a loose connection of one of the wires to the terminal in the switch, but it could be the switch that is faulty.

I repeat, do NOT do it yourself.

Good advice Lindy.
The best that could happen is the light won’t work…
The worst that could happen is a fire behind the wall and up into the floor/or loft above…Don’t do it…Double switches - and especially two way switches can have some very complex wiring.

I have to agree in this case . The problem with switches and sockets is the wiring behind is not that long to pull the front right out. Yes you could undo the existing switch (electricity main fuse off) and try copying from one terminal to the other BUT and a BIG BUT it may also be the wiring causing the switch to fail.

Also the back of the light switch may have terminals in a different layout.

Electricians recommend a rewire of house electrical circuits every 25 years.

My strongest suggestion is to go get the correct light switch and get an electrician in to test and connect for you. That way it cuts down his time in getting a switch for which he would charge you for

[FONT=“Arial Black”]Even if you did it yourself legally you should have a qualified elecrictrician to certify it has been done to IEE regs and signed off[/FONT]

Thanks JBR - that’s the best offer I’ve had all day! It occurs to me that this switch was wired in six years ago when I moved here…that would have been by a qualified electrician, so maybe (hopefully) it’s something simple. Will take the plate off tomorrow and take a photo… thanks again.

I give up, carry on regardless.

No problem.

Rest assured that if there was any doubt about what I see, I would do as others have suggested and advise you to get in an electrician.


I did 5 year apprenticeship as an electrician and have an ordinary national certificate (ONC), now not allowed as not up to latest IEE regs and retired anyway . I don’t think JBR is actually qualified to give advice all be it well intentioned.

For the cost of getting an electrician in who anyway would have to pass your switch wiring under the law it is not worth attempting to do it yourself

Thae a trip to your local fire station and ask how many house fires are due to faulty electrical wiring

The sizzling noise could just be a loose connection - the wires in the terminals can vibrate loose over time (because of A.C. voltage). Turn the power off, unscrew the switch from the wall and check the connections. If okay, then change it. Make a note of the connections or better still, remove the wires one at a time and put the removed wires into the same terminal locations of the new switch.


Certification by a registered third party
3.5 Before work begins, an installer who is not a registered competent person may appoint a registered third-party certifier (electrical contractor or electrician who is a registered member of a Part P registration body) to inspect and test the work as necessary.

I agree and consider it to be irresponsible if not downright criminal to advise someone who stated that she was “hopeless with electric” to try to do this job.