Getting shocked through the wall!
 

I just finished wiring some ceiling light boxes and covering everything with drywall. While applying metal corner tape to the drywall I get zapped right near the area where the boxes were installed.

I did everything right, and used a junction box properly grounded. The only thing I can think of is the circuit is grounding out through the box and somehow electrifiying my wall!

Anyone have any ideas?

Sounds like a misplaced drywall screw/nail.

You'll need to find the punctured Romex. It might be cabling different from what you installed.
Possibly you could ground the corner bead and see which breaker trips.

Actually, it was wet drywall mud contacting a hot on one of the outlets on the opposite side of the room. Current passed right through the metal strip on my corner tape.

I cleaned off the outlet and no more problem. Lesson learned..

Thanks

So wet drywall compound conducts electricity? I'll have to file that one away for future use. And the next day when the compound was dry the problem would have disappeared. . .

With this new information, my guess is then that the breaker would not have tripped with the strip grounded because the current would have been in the mA range but more than 1 mA because with less you would not have felt a shock.

And with the breaker off, an ohmmeter might have shown some resistance between this corner bead and the breaker's terminal.

Good problem, good job. . .

Which is why I always throw a turn of electrician tape around new outlets and switches before the final installation. Also why I use plastic boxes, not metal -- this eliminates the chance of odd contacts like yours.

Congratulations on finding the problem! :)

Wet mud never belongs inside of an electrical junction box.

In new house construction, plugs are never installed before the mudding is done. Breaker should be turned off when mudding drywall, tileing or grouting and if you are a sloppy painter.