You have a chest of drawers that has a wobbly knob. Don't you hate that? You're always afraid you're going to pull the knob off when you open a drawer.
Grab a screw driver and remove the screw from the inside of the cabinet.
Now using nail polish, white glue or wood glue, place a drop in the hole of the knob.
Before the polish or glue dries, replace the screw.
Now when the polish or glue dries, it will securely hold the screw into the knob with out a wobble.