On Fri, 05 Nov 2004 12:46:23 +0000, John Rumm
wrote:

Andrew Gabriel wrote:

I suspect capacitive coupling to a buried cable would do it.
With the plaster all wet and conductive, the capacitance to
something like a light switch drop with both wires live would
be higher than normal.

That was one of my thoughts... although I am not aware of any cables
there (above a window, opposite side of the room from the door).

Can you try a cable detector to see if there are any live cables in
the vicinity?

sPoNiX