You can replace the box with an 'old work' box that is secured in place with tabs in back and in front of the drywall. Some HDs and Lowes, etal carry them, or you may need to go to a better stocked source.
It can be a little tedious to gnaw out the old box without too much damage to the surrounding drywall, depending on the tools you have.

I have never seen a Lowe's or Homer's that didn't carry old work boxes. You will just need to make sure the opening in your wall is correct. Trim it if it's too small. If it's too big, you may be in trouble.

Too remove old boxes, I have a thin bar that has an extremely sharp edge. I wedge it between the box and stud and use a hammer to deliver sharp blows and cut the nail. Works well. You could also use a sawzall...but be very careful you don't hit wires. With either method.

Thank you Randy427 and Cobraguy for your reply. How often do you run into this problem?

I would NOT remove the plastic box simply because of the stripped hole......

Just use a sliver of plastic from another box and a soldering iron to melt a repair to the hole.......

Then use a small drill bit followed by a 6-32 tap.......I keep a triple tap with a screwdriver handle in my pouch for thread chasing......

Sometimes the damaged portion is just part of the available screw boss on the box. Try some 2" long 6-32 flathead screws.

Those last two suggestions are excellent ones!

We use an angle grinder with a metal cut-off wheel to remove old boxes. Takes about 3 seconds.

You have a steady hand Matt! I would end up cutting half the wires with that! LOL

I have heard a lot of suggestions and over the years have tried most of them, like using bigger screws, or glue in the holes and tape on the screws or tooth picks or epoxy. Some work while others make things worst.

there is a clip available that I have used with sucess.
it is just another approach that may help.
www.g-clip.us

The clips do look as if they will work. The person posting registered today and appears to be the same person selling these clips.

I just bump them up to STI size (Steel thread Insert, AKA helicoil) and the problem is fixed.

Just another reason that I prefer metal boxes.

"Just another reason that I prefer metal boxes."
I still prefer them for the overal smaller physical size.

Metal boxes will strip too, then you can be in more trouble.

I've found longer screws work. I've often wondered about those threaded insert things that go in like a pop-rivet. If they made the right size, they'd be perfect. In a plastic box, you could glue them in place.

I would think in the majority of cases, replacing the box is unnecessary. I've had to replace a few plastic ones (especially light fixture octagonals) because they've gotten brittle with age and break away from their mounts. This tends to make light fixtures fall down.

Plastic boxes are ok for outlets and switches, but I wouldn't use them for lights.

Those clips are kind of neat, I'd tend to give the person who posted them a pass, since they actually look like a good idea.

"Metal boxes will strip too, then you can be in more trouble. "

There are multiple simple available tools to repair a stripped metal box.

Helicoils are not useful in thin sheet metal, but internal threaded rivets are.

Drill the hole to clear the rivet, set the rivet, new threads of desired size.

New work electricians often lack a good set of tricks and tools to make repairs to old installations.