Seeing ghosts.

is that even a thing? personally I dont really believe such stuff. but I have seen people claim they do see things. even my cousin brother claims he sees ghosts and has vivid dreams. sometimes he even predicted shit, which I feel like it might be coincidence but idk man. even though when I say I dont believe in such stuff, I do believe there r some things out there which r still a mystery to science.
wt do y'all think? or anyone here has seen ghosts or spirits? I do like knowing new things though. so feel free to share.