Sounds like a Fringe episode.
[ I had a girl ask me if I saw people that were not there. I asked her what she saw and she said people dressed in old cloths. I asked her if they looked at her. and she said no. There are man people with “gifts” that have not developed them. ]
There is a theory that “Ghosts” are Extra Dimensional “Leakage” and that in cases like this they are seeing people from an alternate timeline that has society in a less technologically developed state...
I’ve read that and I’m open to it. Or it could be from our own past timeline. I think ghosts are real, but it’s presumptuous to say with autauthority that they are the actual spirits of the dead, or demons, or anything else.
We just don’t know.
And also, different theories aren’t mutually exclusive.
Sounds like a Fringe episode.