stray voltage

My GFI has one spa light and two pool lights. The spa and one pool light work fine. The second pool light trips the GFI whether there is a bulb in it or not. I have tested three different GFIs and they all act the same. The ground wire for the second pool light is connected to a bus that...

I have a 20x40 inground vinyl pool. Pool installer was very experienced, put in about 8 years ago. The pool was bonded, I remember seeing the green wire around it before concrete and concrete rebar was wired together as well. He showed me some ohms tests showing ground to pump bolt was...