Never seen one.
However, I think I may have been in the presence of spirits when staying at a friends house one night. He happened to tell me that his house was haunted and strange things happen there. I didn't believe him, even if his other friends backed him up with the stories and such, I didn't care, but I'm always interested in hearing these sort of tales.
Still, when I was there a lot of peculiar things happened that could only be defined as strange. Tappings on the wall, scratches through the closet, noises down the hall. And, mind you, we were all in his room waiting for the so called "Ghost" to show us more, but if anything all I got was a picture saved on my camera when I photographed the mirror and saw something lurking in the hall. It had a womanly shape and it looked like it wore a dress. I could almost make out a pair of eyes too.
Today though, I harbor no feelings towards the superstitious events there.
I want to see a ghost. I want to be scared.