Personally, I know there are. My grandpa passed away when I was 7 years old. When I got back from the funeral I was getting ready for bed(my parents were in the living room) and my light kept turning on and off by itself. Since then my lights will still go on and off by themselves on occasion. Doesn't explain anything but I feel its my grandfather. I also will hear crashes and loud noises from my closet and when I open it there is nothing missing and I find a coin on the floor of my closet. My grandfather used to give me coins when I was young as well. Strange I know, thought I'd share.