Fluke is your friend . . .
This is a little 25 buck item I always have in my shirt pocket when I'm working with wiring. Just hold it next to the circuit and it'll tell you if it's live. It's a double check after tagging out the circuit, just to make sure I did the right one . . .
We also have the big Fluke multi-meter. What a godsend that is! (it ain't 25 bucks though!)
