Typically, stripped holes cause loose screws. This happens when someone uses too much force, pressure or speed to screw it into place. The friction of the screw threads against a metal or wood hole rubs away the surface that secures the screw in place. The lack of grooves for the threads to attach to, makes it almost impossible to tighten the screw. In this case, you must remove the screw and fix the hole.
Place needle nose pliers at the top of the screw and push. Gently squeeze the pliers and pull the screw out of the hole. If a screw is beneath the top of the surface where the pliers cannot reach, use a magnet to draw the screw out of the hole.
Cover a toothpick with carpenter's glue. Coat one end of the toothpick and place it into the screw hole. Coat two more toothpicks with glue and place them along the edges of the screw hole. This method creates a new surface for the screw threads to grasp. This works on both metal and wood surfaces.
Allow the toothpicks to dry one hour in the hole. The carpenter's glue needs to set up correctly. Check the strength of the toothpicks by gently pulling or tugging on them after an hour. If the toothpicks are loose, let them sit for another hour.
Place your utility knife over the toothpicks at the top of the screw hole. Score each piece with your knife to make them easier to break off. Break the tops of the toothpicks with your pliers. Run sandpaper over the top of the screw hole and even out any rough edges.
Drill a small start hole. Put your screw on top of the hole and drill it into place. The toothpicks ensure your screws stay in place and keep them from coming loose.
You can use wood matches instead of toothpicks to secure loose screws.