I bought a house, a real fixer-upper One problem is that a lot of the
holes cut in the drywall to fit around the receptacles are too large, so
that the fins on the plug don't catch - it just keeps going till it's flush
with the box, which of course if flush with the stud. So, the plug sits
about 1/2 inch too deep.

What are some methods for fixing this? The best way I could think of is to
buy some longer screws, and some small, thick washers. Any suggestions?