Anybody with a computer can find you and a map to your house within two or three minutes. I was surprised to find an aerial picture of my house--and I was impressed by how impressive it looks from the air! Pictures do lie!
Going to the post office isn't perfectly safe. People in the parking lot may be lurking there to hijack your car or steal your mail as you come out the door.
Most people are honest. You can take reasonable precautions against the others, but the truth is, that if a bad guy wants to get in, s/he can get in.
Relax and quit worrying about the unlikely. Peace and grace,
froggyintexas