On Feb 11, 1:41*pm, wrote:
A simple task, I know.

The GFI in my kids' bathroom went bad.
I installed the new one. *When it's hanging out of the wall, it works.
When I push it back into the box and press the button, I get sparks
and it trips the breaker in the basement.

The damn ground wire keeps popping off, no matter how hard I torque it
down.

All the other wires stay intact...they're the type that plug straight
into a hole in the GFI, then a screw tightens them in.

What's the trick for getting the ground wire in tight?
There's a little metal plate, but the wire doesn't fit under it...so
I'm just trying to tighten it under the screw head.

I'm a little confused. Your post makes it sound like this has happened
multiple times. First off, the ground popping off would not cause
sparks and or a breaker trip unless the ground wire came in contact
with the hot. A GFCI with no ground would operate just fine.

IIRC, the ground screw is on the opposite side of the GFCI from the
hot leads, so it would not only have to pop off, it would need to find
it's way over to the hot lead in order to spark and trip the breaker.
In fact, if it sparks only after you press the Reset button, then the
ground wire would have to have found it's way to Load side hot lead.
Otherwise, if it was touching the Line hot, it would spark and trip as
soon as you turned the breaker on.

I don't have a GFI in front of me, but every image I can pull up on
Google shows the Load hot diagonally opposite the ground screw. How is
the ground wire finding it's way all the way to the load hot while
pushing the device back in the box?

I think you have something else going on besides a loose ground wire.