I've had one notable experience. When I was younger my grandfather lived with us and passed away in our house. A few days later, I came home from work in the middle of the night and heard him say "Hi, [my name]" as if he was sitting next to me. Freaked me out. Within a couple days of that, apparently my stepmom also had an experience involving him. We didn't know about each other's experience until many months later.