Pull up a chair and spill your guts for everyone to see
My mother used to work swing shift (4pm-12am). One night she got sick and came home an hour early. My father heard rustling in the living room and grabbed his gun. He saw someone moving in the living room in the dark As he said "I am sure glad I decided to flip on the lights before I shot." He found my mother undressing in the dark so she wouldn't wake anyone up.
This is how people are killed accidentally. My father said later that he learned that a light switch is more useful than a gun.