Originally Posted by carboranadum
Actually, you'll need to bond your grounds together, right?
I was thinking the same thing, so I went back to the code last night. I can't find anything that requires one to do that. There is some ambiguity in Article 250 that some read as requiring the grounds one circuit being twisted together, and the grounds on the other circuit being twisted together, but not necessarily tying the two circuits together.
Practically speaking, of course, it will be difficult to fold all of those bare wires into a box without them touching, so you'd be better off making a solid connection between them. And if it were a metal box, all of the grounds would be connected to it anyway. But I couldn't find anything that specifically required one to tie all of the grounds into one big connection.