Yeah, I can see where a current sniffer might be nice, but couldn't you just short the wires or lock out the circuit before touching it?
I will share something about cutting sheet metal too.
If you scribe (score) it with a sharp blade, like a utility knife, and start folding it on the scribe line it will come apart there.
You don't want to fold it right over, that would put a bend in the sheet, but just enough to stress the scribed line.
This is effective on steel and on aluminum sheet, often it is the fastest way to cut it. Even faster than a saw.