Truthfully what we have done in the past is set up an appt. to look at the facility (don't give reason other than you are business owners). If it's a real estate agent we ask if the owner(s) will be there and ask if they could be there, if possible. Once we are in person and get a feel for the other person/people then we let our enthusiasm about what we do out and connect with them. This has gotten us farther than just calling and doing it via phone. We've had a few people in the past shut down the phone conversation once we said haunted house.
I know it's kind of nitpicky, but we say things like haunted attraction instead of haunted house...we refer to it to an attraction. That sounds better, I think.

Just my 2 cents...