Ron D. wrote:
David:

You have an old box. Note the bare copper wires under the strain reliefs. You need to dig them out.

These http://www.zoro.com/i/G3705676/?utm_...Zo7 AodHwgAKQ ground clips are eused in that situation.

They are a bit difficult to attach, but The secure a solid pigtail to the side of the box. e.g. the edge that's exposed.

I have to ask. How the hell do you attach or use those things?