I heard of a handy trick!

If you don't have a gun, keep a laser pointer nearby. If someone breaks in and it's dark, point the laser pointer at their chest. They won't know you don't have a gun and it will scare the crap out of an intruder. Of course, hold the pointer away from your body as to not give the intruder your exact position to be target practice for them. So, until I purchase a gun, my home defense in a laser pointer and a golf club. Hehe