When you hear footsteps on the second floor of your home, know for certain there is no one up there and can't see anyone, you gotta wonder where the noises came from.
I know I didn't imagine them. Other folks heard the noises too.
And before you ask, they couldn't be from the house settling.
As for me, I am probably what might be termed a "super skeptic".. ;^) I have had at least four memorable events that others would've interpreted as 'ghosts' - one of which I seriously thought might be a ghost - but none of them persuaded me ultimately.
1) I had come home from work one day when I was in my early 20s, and fallen asleep on the couch. I'd just completed a 16+ hour shift. Anyhow, I was awakened by loud, extended banging at the door (it was roughly around one in the very bright, sunny afternoon). The way the house was built, you could see through a bay window if someone was standing at the door as you were walking from the couch to the door. It looked as if there were a silhouette at the door (beyond the drawn curtains). I looked through the peephole as I always did, and clear as day there was a man in some kind of uniform standing at the door. When I opened the door, there was nothing there. I get chills just remembering it. It's seared .. seared .. into my memory.
2) A couple months afterward, I was sleeping on the bed after another 16+ hour shift. It was around noon. I was right on the side of the bed, facing the direction of the bedroom door. I was half-awakened by the sound of the front door opening but was so dead tired that I couldn't move or open my eyes quite all the way. I saw rather clearly though someone walk through the door and stand at the side of the bed - right in front of me. I was trying to force my eyes all the way open, but I couldn't for what felt like the longest time. Finally, I came fully awake and my eyes opened completely and *flash* there was no one there..
3) Many years afterward, I was visiting the house where my grandfather died. I stayed there for about three months. I was doing renovations to parts of the house. Anyhow, one night I was looking over this one room, which was supposed to be a bedroom but which I wanted to convert into a TV room. The house was generally pretty spartan: no one had lived there for years, although much of the furniture was still there, and it had been kept neat by my grandmother, who dusted, etc. on a regular basis. In any case, I noticed that there was a photo on the wall, which hadn't drawn my attention since I'd been there, because I hardly ever went into that room (I stayed in another bedroom). The room was half-dark, because there was no lamp in there and no light fixture above. I was using the light in the hall to see by. So, I went to look at the photo, and it was my grandparents with me & my sister. Anyhow, as I was looking in this photo the glass front was reflecting me & and the room. All of a sudden, someone stepped into view and was standing right over my shoulder. I turned around and about had a heart attack when no one was there..
I attribute that one to all the hash that my uncle who was also there at the time would smoke, because although I never smoke it I'm very hyper-susceptible to pot and can't be around it in just about any way, shape, or form without it giving me a buzz (i.e., 'contact high').
4) Finally, in one of the houses I grew up in, I would frequently hear the sound of someone running up and down the stairs. Sometimes when I was walking by those stairs it would feel as if someone brushed by me from behind. There was never anyone there at the time. I would also on occasion think I heard my first name as if someone said it from behind right into my ear in a forceful whisper. That all went away when there were major renovations done to the house.
So, anyways, I'm not sure why I told these stories except that I'm bored. I guess that I am a 'hopeless' skeptic. Maybe if I opened the door and the ghost stuck around long enough to hold a conversation, I would believe. =) Perhaps I am beyond redemption..
Incidentally, there's a very intriguing book y'all might want to track down. The Power of Place. It's got a couple chapters dealing with how events that we perceive as paranormal might be attributable to the electromagnetic features of a given place. The entire book is a very interesting read.
I'm pinging Torie so he can remind me what a nutjob I am.