Looking for a part or what it is called..

I've been using whatever kind of limited google foo I have to find a part but it's kinda hard if I don't know the right name of what I'm looking for. Getting pissed.. LOL
my FSM does not call it out. I have the steering wheel off of my 69 barracuda and under what I would call the horn contact copper ring there is a plastic thing that I think would isolate the ground path. It is falling apart. What is it's name and where can I get one from..