Not quite as straightforward as "have you ever seen a ghost?" but in the Victorian tradition of telling spooky tales in the Christmas season, I wondered if anyone has ever seen or met somebody they felt was just a bit...unusual? Otherworldly is the best word I can think of. Or maybe a version of the Uncanny Valley effect?
In my area, I once walked past a pretty, pleasant lady walking two huge white hounds. There was just something striking about them all that I can't put my finger on. I can't explain why but there was just a feeling, which is ridiculous.
Almost like if you'd told me she was a member of the fairy folk I'd have thought ahh that explains it 
I'm aware I sound batshit on this, and I've always had a great imagination! But just for fun, have you ever met or seen (as I didn't really 'meet' this lady) anyone similar?