I've received a call from this number on my cell phone 3 or 4 times now. They never leave a message and I have now blocked it. By the way, the 724 area code is not just in New Castle. It also covers a large part of west-central and southwest Pennsylvania including parts of the Pittsburgh metro area outside of the 412 area code.
Their ploy is when you answer The caller says "oh great you can hear me. The reason I'm calling is because you stayed with us before and…" I tried to stop the man from speaking and tell him I never stayed anywhere but he just keeps talking as if he can't hear me. So I have hung up on him and blocked him. This is the fifth call from that number.