Thanks all. That was it. Any tips for the best way to take two connected faces and put each on a different layer without creating them separately?

I'm assuming being on the newbie channel means not having to say "sorry if this is a stupid question"

It's not supposed to be possible, but I have several faces without edges. The way I created them (I think) is by creating a box, then grouping each of the four sides separately, then moving those four sides to a new layer and hiding that layer. Now, I can't find the 'edge' of the 'floor' or 'ceiling' faces. It shows 'on face', but does not snap to the edge or corner. I need to somehow trace the edges back onto the floor but I can't figure out how. Any suggestions?

Oh, and "Martin says this is the best newbie forum on Earth."