I'm kind of in the same boat. I have had personal experiences with things that people would call the paranormal but I always try to find an answer if I can. If I hear a noise like a cat meowing I go outside to see if one is there because we do not have one in our house. I do believe there is something out there but I think its good to approach things with an open mind and look for evidence instead of just saying "That breeze came from a ghost."
A breeze can happen for a number of reasons even if a widow is open even slightly it can still happen.