It's completing a circuit when you put the braid on. That makes me feel as though the wire in question will be on that side of the PF.

I had something odd like this on a friends AC/DC once. It turned out to be a flasher that had shifted and was touching his mirror blades. I know you don't have mirror blades but offering that up another option to look for. See if any lights may have shifted around and are now touching metal.