1. clean up the back of the hole, so there are no crumbly pieces sticking out behind
2. cut a piece of cardboard (pizza box might work fine) that is about 1-2 inches larger on each side than the hole
3. Punch a small hole in the cardboard, just big enough for a piece of sturdy twine. Put the twine through the hole and secure so that it can't pull out. (Leave the twine long enough for the next steps)
4. butter the outer edges of the cardboard with spackle (or you can use sticky white glue)
5. fold the cardboard in half. (you may want to pre-fold before buttering)
6. slide the "closed" cardboard into the hole while holding the length of twine
7. open the cardboard like an umbrella and pull it towards you, so it makes firm contact with the back of the wall
8. secure the patch in place by tying the twine to something across the front of the patch (a pencil if it is a small hole, a dowel or a coathangar if it is larger.
9. allow to dry overnight.
10. once dry, fill the hole with thin layers of spackle, until even with the front face of wall
11. sand smooth and flush
12. check this post for painting ideas: http://www.houserepairtalk.com/f45/r...ng-wall-17865/