On the mission where you go to the hotel, go to the top floor, where it is deserted. There is a POLICE DO NOT CROSS on yellow tape that has been cut. Go into that room and you should see a dead man. Then go into the bathroom and look into the mirror in first-person view, keep looking at it and soon there will be a ghost of the man who had died, he will then disappear for a few seconds, then comes back. It does this in most of the mirrors in the bathrooms on that floor.