We’re all spirits in a sense.
Some of us may be more spirited than others at times.
Some of us may seem to haunt our own lives.
Simply put, we’re made of energy.
And, it may just be that out-of-body spirits aren’t so much as spooky supernatural entities, but rather run of the mill natural extensions of that same energy they were when they were in-bodied.
Although, the supernatural angle does make for better spooky ghost stories.