Stepping out of the shower one morning, I slipped and almost broke my hip. Fortunately, I was able to grab on to the towel bar and stop my fall. The down side was that I pulled the towel bar holder cleanly off of the wall. It was a nice clean round hole directly between two studs. Some may feel that the simplest way to fix this hole would be to cut the sheetrock until you can span two studs. Here's how to fix that small hole AND make that repair stronger than the original.
The tools and materials you'll need are:
1 or 2 wood shims
3 wood screws (one for flat surfaces, two for countersink holes)
1 flat washer
set of drill bits
sharp utility knife
First, trim the edges of the hole to make it relatively square using a utility knife.
Using your drill and a small bit, drill a hole through the center of both shims.
Put the flat surface screw (and flat washer if needed) through this piece of wood. Then screw the screw into the second piece of wood. You may want to drill out the hole a little in the scond piece of wood so that the threads of the screw will bite into the wood, but certainly don't make it too big where the screw will slip through. Don't screw the screw all the way down so that the two pieces of wood are locked together. You need space between the two pieces of wood.
Now, with the screw holding both pieces of wood, slip the bottom one into the hole and center it. Take the top piece of wood and turn it 90 degrees to the orientation of the piece that is inside of the wall. Screw down onto the screw until the top piece of wood rest against the wall and holds the two pieces of wood in place at the center of the hole.
Replace the drill bit with a bit that has a diameter a little bit large than the head of the counter sink screw. In the hole that was just drilled in the sheeet rock, enlarge the hole so that the screw head will fall below the surface of the sheetrock when screwed in to place.
Screw the screw into the hole. Not too tightly though. You don't want to split and shatter the wood.
Do the same to the other side.
You now have a relatively strong "back-plate" to support your sheetrock patch so that it doesn't fall inside of the hole.
Cut a piece sheetrock that will fit the hole. Don't wory if it doesn't fit that well; slightly loose is better.
Trim the edges and also put a bevel on the near side of the patch.
Trim the edges of the hole in the wall to amke a slight bevel on the edges.
Drill a hole in the very center of the patch.
Check that the patch will sit in the hole, the screw will go through the center and catch the back-plate. There should also be a V around the perimeter of the patch that will accommodate spackle.
Unscrew the screw and take the patch out of the hole.
Take some spackle and smear a little on the back-plate and on the back of the patch. Install the patch.
Install the screw and wood, but put wax paper over the spackle so that wood won't stick.