Bought a house that has a pool that has not been in operation for the last 6 years. The pool light had a cover over it by previous owner. Pool light that was in it... not to be found. It is an American Prosucts CN-5 fixture niche. Pool was installed in mid 80's.  I'm wanting to install a new light. Just not sure what will fit my niche. Looking a 120v, Pentair 5g white light, 100' cord. How can I confirm that this will work?