On 5/28/2015 2:41 PM, Pat wrote:

I just replaced a bad GFI outlet that was in an outdoor fixture. It
would trip within a second even with no load connected. When I got it
back inside to look at it, I could see it was full of whispy white
spider webs. Every hole (3 per outlet) plus the holes on the back
where the wires attach were white.

Since I needed the pump running right away (I just put in phosphate
remover yesterday and it needs to be filtered out) I ran out and found a
240V 20A breaker at the surplus store for $3.25. No GFI but it'll be
okay until the GFI breaker arrives tomorrow or Monday. The breaker for
the pool pump at the main panel is only 20A anyway so the 50A GFI at the
sub-panel was a little over-kill. Pump is running and I didn't get any
shocks.

This is not an outlet with any real openings for anything to get into
but I guess after ten years the GFI circuit failed in some way.