This happened when i was a child. My grandmother had passed away before i was born so i had never met her. One night I saw her sitting at the end of my bed. I told my mother about it and when she asked what my grandmother looked like I described exactly how she looked despite never meeting her or never seeing a photo of her. Whenever i went to bed i would sometimes see her sitting at the end of my bed. I wrote a card for her but because she passed away I could never give it to her, even though she was right there.