I"d replase it pronto, and if the next one does the
same thing, there's something "differnt" somewhere. A
GFCI, AFAIK, only hums when it's defective or under
heavy load. The TEST button is an indicator of whether
it's working or not, but it's NOT necessarily an
indicator that it's tripping WHEN it should, or of how
much protection it's affording. Stuff happens, so
check it out. Is this new? How long has it been doing
that? Etc.

While you're at it, check out the rest of the things on
that line; is there a heavy load there and is the
switch rated to handle it? Is everything else working
correctly?

Cheers,


"CL (dnoyeB) Gilbert"
wrote in message
...
The GFCI in my bathroom has always made a very slight
humming noise. None of the others make this noise.
It seems to work and the Test button works. Should I
replace it anyway? ever heard of this?





--
Respectfully,


CL Gilbert