My boyfriend had a dream with my grandfather who passed last year and he never met

My boyfriend last night all of a sudden woke up and quickly touched me. I asked what was wrong but he told me he didn't want to talk about it, until today. My grandfather passed away last year exactly a week before my birthday he raised like I was his own blood or even better. My boyfriends dream started with him in the kitchen getting some "peanut soup" and he heard a noise in the basement so he went to go check it out. He says it was dark but he could see a dark shadow he couldn't see a face but he could make out that the shadow was of a built guy and had wet looking hair with a curl on the head. The shadow then approached him stood next to him and then walked through a wall.... I don't know if it means something my boyfriends says he didn't feel threatened as in a bad tension when you feel someone doesn't like you he was just creeped out because he's never experienced a dream like that before. The part that gets me is that wet looking hair and that swirl he especifically described to me its my grandfather's hair style that he would do every single day. My boyfriend hasn't met him at all for him to describe such thing... is just weird I'm lost for words.