Man, I get this one every other week too, so here's a sticky on this ultra simple repair.
Stripped out Strap Button Screw
Supplies needed: One or two wooden toothpicks or one, small, wooden match stick, scissors/wire cutters/knife, white Elmers type glue or wood glue.
The problem is that the hole for the screw is too big and the screw won't grab the wood anymore and hold on. We need to add some wood back into the hole to give the screw something to bite into and hold.
Take a toothpick and stick it in the hole to see how far it goes in. It shouldn't be much more than an inch and a half if that even. Using the scissors/wire cutters/knife, or your own brute strength

, cut the toothpick off so it's no longer than the screw hole is deep. If it's a little shorter than the hole, that's ok. Depending on how sloppy the hole is, if you've got flat or round toothpicks, etc, you might need more than one. If you don't have any toothpicks you can use a wooden match. For safety's sake I'd go ahead and strike the match and extinguish it right away or remove the match head.
Dab some glue on the entire toothpick/s and then shove down in the hole. Insert the screw and strap button and screw it in. Still too loose? Add another toothpick. Just check the button for firmness right now. Let the guitar sit overnight before you use your strap. That easy.
