"Dave Plowman (News)" wrote in message ...
In article ,
Pinot Grigio pinotgrigio@somewhere wrote:
Whenever we turn a light on or off, an electrical sound can be heard
from the PC speakers. I assume we have a faulty connection somewhere.
Any suggestion as to the best place to start. Is it more likely to be
the lighting circuit? I suspect the answer is that it could be anywhere
but just thought I'd ask!

Are the speakers driven off a separate amplifier fed from the mains?

Is it all lights or just one and if its one is it a flourescent light.
These can often cause arcing at the switch contact, ruin the switch
and then generate lots of RF energy that will probably be picked up by
the amplifier/speakers