What does the white wire clip to?

Del

I bet that black wire that connected to the back side of the old voltage limiter was the ground and was needed. I replaced my old limiter with a new IVR upgrade and there wasnt a prong coming off the back of the new limiter like the old one had. I asked about it on another post and they said its just a ground not needed. Well guess what that damn wire could be all my problems. Can I just solder a tab off the back of the new IVR limiter and reconnect the black wire?