A few years ago I lived in a small country town in Australia. I moved into an old rosewood cottage, about 100 yrs old and with a very dark rosewood exterior. My mother christened it 'the Black House'.
I never felt uncomfortable there until one night a friend (I'll call him Paul) came over and we were sitting up late talking and watching TV. We were sitting on the couch and I was facing him. All of a sudden he went pale and said, looking at the window "Did you see that?" "What?" I replied and turned to look at the window, seeing nothing out of the ordinary. "What did you see?" I asked him. "A young girl, I think it was a girl - she had short brown hair and a light blue football jersey on. She was trying to get to or out of the window...but I could sort of see right through her."
He was visibly shaken and I got chills all over as he told me what he had seen.
I resolved to investigate the occurrence, and next time I saw the house owners I asked whether anyone matching that description had ever lived in the house. He looked at me amazed and explained that his sister had died there from an asthma attack when she was about 15, on that very date. He stated he had a photo of her wearing the same outfit, which neither *Paul nor I could ever have possibly seen previous to this.
I never actually saw her or felt her presence, nor experienced any unearthly activity, but I believe that *Paul saw her ghost attempting to open the window to get air.
Neither Paul nor I have any reason to make this up and I believe he definitely saw something that is difficult to explain in any other way than the paranormal.