"Toller" wrote in message ...
99.99% of the time there is nothing wrong with it. However, there can be a
situation where you open the breaker, verify the circuit is dead, and then
find out there is voltage on the ground from the other circuit.
Unlikely, but possible.

Not at all unlikely. I found that out the hard way but getting
shocked off the white wire. Feed to outside yard light runs
underground and has common white with another underground feed to a
shed. Circuit is non fixable without replacing the underground feeds.
At leas now, every box the two circuits run through are prominently
marked warning anyone working in them to pull -both- breakers.

Harry K