Buzzing/humming lightswitch (not dimmer) even when mains off

[sools]

Hello and thanks in advance for anyone who can provide advice. Sorry if its a bit long winded.

One of our light switches started making a low buzzing/humming noise. The switch is a standard, white plastic, one way. (Not a dimmer switch). The buzzing was first noticed yesterday, when the light wasnt even switched on.

Later last night, while asleep, we both heard a sudden louder noise, decided whilst half-asleep it was a proper arcing sound (but with hind sight it probably wasnt!), so I immediately turned off the consumer unit and all fuses.

The strange thing is that the original humming continued even with all mains power off until morning.

All connectors look sound in both switch and rose (I replaced both face plates about 3 months ago, have double-checked connections against diagrams.) So we switched power back on and no problem.

the buzzing still remains and the question is - what could be causing this? even with mains power off?

many thanks if anyone can answer our puzzle!

 

[industryspark]

bee hive?

been out clubbing and stood too close to the speakers?



only kidding, sorry.

did you turn off the switch to the consumer unit killing all the circuits and not just the circuit you thought was giving the problem?

sure it was off? try things to confirm this?

is anything behind or near the switch where you can here the buzzing from?

to be honest i cant really see how with all power off you can have a problem like this thats related to the electrics.

 

[sools]

thanks, what a quick reply.

yes, we did switch off CU and remove all fuse cartridges (70s box, needs modernising)
Then, the light didnt work. But the noise remained: quiet, high pitched. There is no alarm etc nearby, that we know of.

I do know this sounds a bit silly so appreciate the response. Cheers!

We will get a spark in soon (to replace the fuse box), so will ask him about it.