is there a hole or holes for screws? my pool light, which is older, uses one screw to anchor at the top..otherwise, water pressure seems to hold the bottom in. maybe you have my situation which is the pool yokels used a non stainless steel screw when they put it back in this year (they take it out, put on my deck and cover over the winter). the screw completely rusted out. i would imagine you'd see some rust staining if that was the case though?