Hairy Worm ID?

[Ron99]

Firstly I have to say sorry as I can't get a picture. it comes out in the dark and retreats into the live rock when I put anything but a dim red light on it. The worm is translucent grey white and stretchy like a peanut worm but it has long "hair" along its body. These are fairly long; much more than what I have seen on bristle worms. I have seen it poke out of the rock quickly to scavenge some errant food at times so I figured it was a harmless scavenger. However, yesterday morning i noticed a few white spots on a frag of SPS in my tank and last night I saw the worm moving around on the frag.

So does anybody have any thoughts on SPS nipping hairy worms? I have tried searching on wetweb media etc. but can't find anything like it. I will try to get or set up some sort of trap.