I have 12 volt LED programmable lights and they one in the deep end has been intermittent lately. No water in housing and I would not suspect transformer in that the other light is fine. These are the types of LED's that change colors on the fly and have various preset programs. The pool is about 8 years old and we have never had any trouble with the lights. It was nothing to do with the GFCI, the one fixture just comes on whenever it feels like it. It's not dim when it does it will act fine in it's sequences and then cut out. Anyone have a problem like this before?