I have been researching my family history for some time now. And I think my long dead great-great-grandma came to see if I was doing everything right.
Here's my experience:
I was lying half-asleep one night about 5 years ago. I had my eyes closed when I suddenly "felt" something, like a presence, standing in the doorway of my bedroom. At first I thought it was my mother, so I called out to her and asked her what she wanted. That's when I noted the figure looked nothing like my mother. It had a long dress on, styled somewhere in the 1860s period, with its hair up in a bun. Out of nowhere a quick flash of light illuminated its face (it was the middle of winter, so it wasn't lightning, and there was no one else up. I cannot figure out, to this day, where this light came from). When the light flashed, the figure's face was lit up for a brief moment and I noted it was an elderly woman, with big bright eyes and grayish hair. I gasped and pulled the covers over my head. I stayed this way for a long time until I gathered up enough courage to peek out. The figure was gone.
A few days later I was researching the family history when I came across a photo that had been buried deep within a box. I pulled it out, turned it over, and nearly fell on the floor. It was the same lady I had seen that night! I know I'd never seen that picture before then. The picture had no writing to tell me who the lady was, so I took the picture to my great-uncle, the family historian. That's when he told me the photo was of his mother, taken shortly before she died.
Did my great-great-grandma come back from the dead to look in on her sleepy descendant? I think so, and I don't think I was dreaming either.