I stumbled across a book called The Haunting and its a Harlequin book that sounded really interesting to me. So my question is what romance books are there that are about old houses, hauntings, ghosts, reincarnation, paranormal, or the supernatural? I have never read any Harlequin or books like it and would be interested in reading them if they were about any of these things.

Oooh - The Haunting by Hope Tarr is one of my favorite HQ Blazes. 

It sounds like you are looking for what I refer to as paranormal "lite".   HQ/Silouette has a paranormal brand called Nocturne, but those tend to be deeper into the paranormal/fantasy world (vampires, werewolves, etc.)   If you are looking for paranormal "lite", then you will usually find those scattered in amongst the other HQ brands.    I'll review my books read and see if I can make some recommendations for you later.

And then of course, there are plenty of romances featuring paranormal elements that are NOT published by Harlequin.    I just finished Jennifer Crusie's latest - Maybe This Time, which was set in a haunted house.

Heather Graham has a good series.  You can look her up on Goodreads.

I have read alot of Heather Graham books, I like those. I like that the Harlequin books are so small. I'm not really into vampires or werewolves, I really like ghosts and haunted houses. Thanks you guys for all your help.

I liked these 2 (harleqin american romances) Daddy Warlock (Diamond)and One More Valentine(Stuart)

someone recommendd this one to me once but I never got around to reading it because I thought it might be sad - Love Bites

saw these while browsing - nickie's ghost, ghost of a chance (both american romances)

I was just going to recommend Heather Graham as well. She's a favorite of  mine.  The romance is not always a huge part of the story.

I don't like the little series romances so I can't suggest any of those.