My father was a skeptical man in most arenas, but susceptible to the interesting collection of old Scottish ghost/folk stories he'd grown up with.

He was, I think, almost convinced the Second Sight was a real phenomena, doubtful about fore-runners, and ambivalent about ghosts.

One night, when he was around sixty, he woke to see a figure standing by his bed and staring down at him. Un-nerved, to say the least, he closed his eyes, and when he opened them again, the figure was gone. Next night, he woke and there were several people moving about the room, pausing to stare at him. He again closed his eyes and they went away. He was convinced he was seeing ghosts, but didn't recognize any of them and was quite frightened by the experience. The third night, he woke to see.... a refrigerator full of food, door open, light on - real as anything, he said.

Right, he told me later, I don't think ghosts of refrigerators are likely, so off I went to the doctor.

Turns out a fairly rare side effect of a medication he'd recently started is vivid hallucinations. But if the frig hadn't appeared, he'd have continued thinking the visions were indeed ghosts.