My father died at 39, I was 13 at the time. It was a few months after he died I was home alone and decided I'd do something nice for my mom while she was out and cleaned up the house. After I was done I went in the basement and watched TV.
All of a sudden I hear footsteps upstairs, and the sliding of a chair across the floor. Excited, I thought my mom was home and rushed upstairs to greet her and see her appreciation for cleaning the house. Problem was.....there was no one in the house, she wasn't home yet, but the chair had been moved into the corner of the kitchen kitty corner to the small table, exactly the way it was when my father would have his morning coffees.
Didn't take me long to run out of the house freaked out of my mind.