Sometimes you find a hole that is too large for your screw to grab into because of wiggleing or stress over time. Well if it wieghs a lot you might want to drill a new hole. But, for a simple and easy fix all you have to do is grab about 1-3 tooth picks and put them in the hole and break off the ends. Now you can drive the screw in and it will have something to thread into without comeing out. And you have saved patching an old hole and about 10 minutes.