The problem is Roy, that you may have seen a ghost, but you didn't know,? people walking down a country lane, and some one passes them, you think nothing of it, you sit on a bus, and the bus is empty suff for a guy sitting a the front/back of the bus,?
an old bombed collage you see a person walking across the ruins, only problem is this person is walking about 12 inch's above the ground, ( where the old floor should have been,) ? people who live in a house with a gravel drive, they hear some one walking up the drive, but when they look they don't see any one, but they hear the sound of feet on the gravel....boo..
But a lot can be shown that there is nothing super natural about it.. even for me in my street where I used to live, after the war people would say they could hear voice's of the dead, when you walked by a bombed site at the bottom of the road, yes, it was strange,
later the council people came because there was a water leak and they had to find it, they used to carry a stick which they would put one end to their ear, and the other to the ground, and listen for the sound of water, when asked what they where doing ( me as a little kid), they let me listen to the sounds of the street, I can hear people talking I said, no son that the sewer and it echos along the pipe, ...so now I found out why the dead people talked.. naa they where living down the street and you could hear them at the other end,