Thin free swimming worm at night attracted to light


Reefing newb
at night here and there I find when i shine a light in the tank one or two very skinny rapidly wiggling/swimming worm appears. It is obviously attracted to light. by skinny I mean thicker than a hair and thinner than the thinnest angel hair pasta they make.

Any ideas? I don't have any pictures of it.
I dont know what those are called,but I see them every night in my tank.I assume they are safe since I've seen anything to suggest otherwise.
Its free swimming and looks like a short very fine piece of pasta. swimming/wiggling in the water column.
Any chance anyone feels a parasite treatment is in order? I've done some digging and I wonder if there is a chance its parasitic.