This is the only experience I've ever had with a so-called ghost that I cannot explain.
Several years ago, I was asked by an elderly couple to rewire their living room lights. I had never met them before (a friend introduced me to them), but they seemed like friendly and honest people.
On the day I went to their house to do the work, the old gentleman began telling me about the ghost that was in the attic. He said that he and his wife had moved into that house twenty years ago. Two years after they'd moved in, there was a hit and run accident in the street directly in front of their house. An eight year old girl who lived in the neighborhood had been run over and killed. According to the older gentleman the driver was never caught.
After a few months had passed the couple began to hear the voice of a child coming from their attic. They would go up to investigate, but there was never anyone there. This went on for about a year, until one day, while carrying some boxes to the attic for storage, the woman found a drawing that looked as though it had been done by a child. She didn't think much of it at first, but as time went on, more drawings began to appear.
At this point in the conversation, the woman led me into the kitchen, opened a counter drawer, and produced a stack of drawings. The pictures showed simple stick figures that appeared to be drawn with crayon, looking like something a child would draw. The thing I found interesting, though, was that they all had been drawn on half pages of old news papers, bits of cardboard, or anything else she had in the attic (I had assumed the pictures would be on neat sheets of paper). I asked the woman if someone might be joking around with them, but she told me they rarely had visitors, and no one was allowed in the attic.
We returned to the living room and they continued with the story. After a few years of hearing the voice and finding the occasional drawing, the couple said that stranger things began to happen, especially around the anniversary of the little girl's death. The woman said she would find what looked like drops of blood on the countertops or on the kitchen table. The man told me that tools would disappear from his tool kit, then somehow always end up in the attic. I asked them why, if they believed they had a ghost in their house, hadn't they packed up and moved away. The woman told me they never felt threatened by the ghost. She said that she felt pity more than anything else, and that somehow the little girl could sense this.
Being the skeptic that I am, I couldn't help but think how cliche their story was. I wanted to ask them if the girl didn't originally live in that house, then why would her ghost decide to move into their attic? Still, I was polite and kept my skepticism to myself.
Before setting off to work, I asked the man where the breaker box was to shut off the breaker leading to the living room. He directed me to a small room leading off from the back of the kitchen. After I'd shut off the power, I returned to the living room and assured him that it should take no more than 15 minutes to complete the job. That's when the man laughed and told me that it would take much longer than that. When I asked him what he meant (feeling somewhat insulted) he said that the girl's ghost was very mischievous, and would most likely play little tricks on me. I was getting annoyed with their ghost story so I immediately went to work on the lights
Basically, the couple had cut a section out of the wall between the living room and the dining room and installed a counter. My job was to rewire the living room and dining room light fixtures to the same switch. No biggie at all.
Yet, the damn thing took me all day to finish. I checked the wiring leading from the switch to the two fixtures with my DVM and everything looked fine. I hooked everything up, turned the breaker back on, flipped the light switch, and nothing happened. I removed the fixtures again, checked for continuity, and everything looked good. So, I hooked it all back up, flipped the switch, and again neither set of lights lit up.
The second time I checked the wiring, I couldn't get any continuity at all (meaning that there might be a break in the wire). Even though the wire looked in good shape, I decided to replace it with new cable. After I did this, I once again checked everything, and it all appeared good, so I hooked it back up. Again nothing happened. The whole time I was working, the man was siting off to one side watching me with a smile.
I finally removed both fixtures and ran jumpers to them. Every time I flipped the switch, both sets of lights went on. I removed the jumpers, replaced the fixtures, and still they wouldn't work. I checked for shorts and open circuits all along the wiring back to the light switch, using both a DVM and an analog meter, and I couldn't find the problem. I decided to check the switch itself, and when I did, I found that there was no juice flowing through. I felt like kicking myself for not having checked it sooner. After removing it and checking it again, I went and bought a new switch, installed it, and tested it. The current was flowing through it just like it should, so I hooked the whole thing up, satisfied that I had found the problem.
I felt like punching my hand through the wall when the damn thing still didn't work. I was completely embarrasses as I turned to the man and began to apologize. The old gentleman rose from his chair, walked over and flipped the switch. Both damn light fixtures lit up!
He laughed and said, "See, I told you she was mischievous." I flipped the light switch on and off myself and it worked just it should have.
For years I went through this over and over in my mind. One explanation why the lights didn't work could be that someone was turning the breaker on and off. The problem with this is that the only people in the house were the couple and myself. The only way to get to the breaker box was through the kitchen. The man had sat watching me the whole time so he couldn't have switched off the breaker. The woman walked in and out of the kitchen while she did her chores, but I never saw her go near the back room. They might have had another connection to the dining room switch, but I think that idea is stretching it a bit.
And even if someone was turning the breaker on and off, I still can't explain the continuity problem. I tested and retested the both the old and new cables and the switch, and they were showing completely open circuits. Yet, after the lights finally worked, I tested the old cable and switch and found nothing wrong with them. And both my meters were in perfect working order.
If I heard this story from someone else, the first thing I would suspect is someone was tampering with the breaker, coupled with human error.
But I was there, and I know how thorough I was. I did eventually search the local papers and found that there had been a hit and run where an eight year old girl had been killed, but it occurred two blocks away from the old couple's house, and not directly in front of it as they had stated.
The couple has since passed away, and there's been new owners there for years. There's no way, however, that I'm going to knock on the door and ask them if they've seen the little girl's ghost.
I still don't believe in ghosts, but I still can't explain this either.