I saw a free floating column of white light at my grandmother's house one time. It had the vague outline of a person, standing in the hallway.
I don't abuse any substances that would cause any hallucinations. It was during the day, about three weeks after my grandfather died. The thing is, at the time I didn't believe in Ghosts, and to have seen that turned me into a believer reaaaally fast.
My dad is turning into a believer now as well, and has been going with a local Paranormal Investigative team, that went to the town Court House this past week. On one of the video cameras, you can see a whiteish outline of a person walking by the camera really fast, when no one was in front of the camera at all. There were people in the room, but they were not moving and no lights were turned on.
Was extremely creepy. I was looking at the video *Raw footage, as in the tape has never been removed from the camera* and was like "WTF?!?".