That does not look like a glow plug wire. It wouldn't have 2 wires and that double spade connector. My guess is it's a ground connection that broke off somewhere in the vicinity.
Bought a precision ground rod to align my lathe. Found a paper tube close to the right size wrapped it in duct tape and put spray grease in the tube. Just trying to preserve it for the few times I'll actually use it.
Picked this up somewhere years ago came with some other stuff. I think it's for stamping something. Under the thumbwheel is a reversible die that appears to have US on one side and oz on the other. Doesn't appear to be adjustable for thickness of material.