[FirstYorkie]

Sounds like you have a very smart pup. She has learned what displeases you and, because the sound of your "NO!" upsets her, she is careful not to do these things where you can see her.

Management might be your best tool.

As for chewing the wires, clear solid rub-on deodorant works wonders. Try rubbing some on those wires and see if it stops the behavior.

For humping, hmmm... I can think of 2 options. Keep her toys picked up so that she can't sneak off and hump them. Or, <gasp> allow her to do it. I personally hate to see dogs humping things. But, if she's hiding anyway when she's doing it and you don't have to watch it, then I don't see any reason to make her stop.