"charles adams" wrote in message
Thanks, but what the 'ng 'll is capacatitive coupling?!. Please answer
as if to a flatliner!

An electrical charge induced in one wire in close proximity to another wire
with a voltage on it.
Or even simpler if the switch is off, there is still a small amount of
electricity on the off side of the switch, Not enough to bite (usually :-)
but enough to light a bulb now and then.