They are 6-NF/32 threads are the ones that go into the box at the top and bottom. And the ones in the plate covers. The other two most common sizes are 8-NF/32 and 10-NC/24 used in electrical work. That is the three sizes on my Gardner Bender rethreading tool. I buy the screws in what ever size I need and swap them out. They also have little plastic thingies that can hold the boxes out from the original mounting position.
the big boxe stores have both in the electrical dept.
Been there, probably broke it, doing that!
I am not a lawyer, and never played one on TV!
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