Buzzing and cutting out from oven/hob switches

[Glastoun]

I unscrewed the frontplates from our oven/hob switches so I could plaster around them and the chases (CU off). The wires are quite short so they only come out 15-20mm or so. Circuits are new and were installed about 4 months ago.

After plastering, when I screw them back one of them buzzes, and the other one cuts in and out a few times every second.

The buzzing one, if I unscrew it and let it sit away from the wall it doesn't buzz, or at least if I move the frontplate I can stop the buzzing. So I assume I've loosened some of the wires inside when I was moving it to plaster?

Should I just get this checked by an electrician, or can I try to tighten up the wires as if I was fitting a replacement frontplate? I'm fine with wires, but they're a bit fiddly as they're so short, and I'm not keen on the whole 'death' thing.

 

[PrenticeBoyofDerry]

Sounds very much like a loose connection, this can be dealt with easy enough. After safely isolating, tighten the terminals up.
If you find conductors are too short they can always be extended using the correctly rated connectors and cable within the backbox.

Another issue could be that the face plate is faulty, if not loose connections.