Pool Light Niche safety

I have a very old spa/pool with a Hayward SP-558 wet niche. The light has been dead in it since I bought the house 2 years ago.

I am renovating and want to replace the old dead light with a modern LED light.

The problem is, nothing fits this ancient niche. It is 5.5" ID and 7.5" OD which is far bigger than modern spa lights, but smaller than pool lights.

My question is, if I accept that a modern light wont "fit" in that I can screw it in but it doesn't snug to the niche, is it safe to install a modern light that is technically too small. The ground is there and the conduit is clear to pull a fresh light.

The alternative is probably a couple of thousand dollars to break out the old niche and patch in a modern one. That just isn't worth it to me.

Thanks for any help!

Anyone?

Not too many folks with answers about "ancient light niches". In Chattanooga, there's one old guy (even older than me!) who'd probably know what you are dealing with . . . IF that niche has been used in this region. But, he wouldn't work on your niche, unless he'd built the pool.

I think that's going to be a pretty common problem -- the few who have the experience aren't interested.

If I were going to try to solve your problem locally, based on your description, I'd have a custom SS ring fabricated by a custom sheet metal shop, so the ring would mount on your niche, and a spa light could be mounted on the ring.