Well, It happened when I was really little and I'm not sure if anyone will believe me, but here is some background. My grandma Virginia died of cancer when my dad was only 17. So I could have never met her.

I was little and was having nightmares frequently and I refused to sleep in my own bed. I would have rather slept next to my parents bed, or door. So anyway, I woke up because I heard something and I looked and saw a pale old woman standing there. Being only like 4 or 5, I froze in terror and when she took a step towards me I quickly pulled the covers over my head and I do remember falling asleep again after checking multiple times to make sure that the lady was gone. My mom was really weirded out because I had never seen my grandma's picture at all and I described perfectly.

If anyone has any explanation I'll be glad to hear it :)