The Luftwaffe Pilot
This happened during the Cold War, in West Berlin, at a military installation which was built in the 1930s as a German Air Training school. I knew nothing about the "haunting" when I was there on a short tour of duty.
Every time I descended the main (stone) staircase, I felt I was being watched, and that someone wanted to get my attention. This feeling increased, until I felt shoved, and had to grasp the banisters to stop from falling. I'm not particularly psychic, despite having Celtic ancestry. Any subliminal visual impressions usually hit me, like a rewound movie, just before I fall asleep. This time, I was on the stairs and behind me, looking over the parapet, was a tall blond man in a dusty greyish uniform. The look of anguish in his face just horrified me. I did my best to ignore the impressions and the dreams, and soon was left with only a hideous depression. Fortunately, the visit was only a week, and I wasn't reminded of it until some years later when an army acquaintance, who'd also stayed at G---- was talking about the ghost.
It seems that during the Allied Advance, in April 1945, the fighting around the local woods was fierce. Eventually, the USAF bombed the place, and at least one Luftwaffe pilot, trapped in the basement air raid shelter was killed, but it was impossible to get any bodies out (there are loads of undiscovered human remains in Berlin). My friend was describing the ghost, and I was able to finish the description. He has been seen, heard and felt for many years. Like so many lost souls, he wants to be recognised, have his bones buried properly. Usually, as in this case, impossible...