I know it can be easy to get wrapped up in the stories of the home sellers but when it comes to things like haunted houses or spiritual mishaps, don't speak of it to potential buyers. It is advised by both agents and home owners to avoid the conversations of such things regardless how they feel about it. You are not obligated to say yes or no.
I have heard of people doing this, mostly home owners, and it resulted in their homes being on the market for much longer. It interrupts sales and causes people to look at other options.
For some people, it might be a selling point but for most it just isn't. This is especially true for families with children. I once saw a man lose a sale over a kid finding out there was hauntings in the house.