All good answers. Are there a lot of burglaries in your neighborhood? If not, tell yourself you're being paranoid & force yourself to think of better things. If there are...great ideas above. Leave on porch lights, get a dog, pepper spray or tasser, install deadbolts OR (if you can) move!
I was always terrified that someone would break into our house and Hirt us. Then I realized that I've never heard of a crime happening on our ridge. It gave me a little bit of relief. Then we got a great Dane. I wasn't scared anymore