The other day in class, we were talking about how ghosts are often perceived as sticking around because they have unfinished business here on earth. For example, the ghost of Hamlet Sr. is still around because his son has not avenged him yet. This is also exemplified in Beloved through the ghost of the baby.
When we were talking about this in class, I got to thinking about a show that some of y'all may have heard of called Long Island Medium. Basically, this woman claims to be able to talk to ghosts, and in her episodes she speaks with the dead and helps those on earth communicate with their loved ones who have passed on.
Here's a link to one of the Medium's readings: