At what age is it okay to tell ghost stories to kids? Is it healthy to, though?

Why would you want to tell Ghost Stories to kids? I think let's not get into that space as kids are really very sensitive and tend to recall things which might affect them. I used to wake up in the night as a kid and scream (Must be about 4-5)... Mom still recalls that day when she told me a ghost story and I gave her sleepless nights for 2 months'... So I say NOPE