 Brian in Arkansas is on the line and has a mysterious odor in the house. What's going on? I've got a crawl space under my house of about 1,900 square feet. And we've noticed the last several years, only in the summer, when we go away from a long weekend, we come back on a Sunday night and there's a peculiar odor in the house. It's a musty smell, if you will. But again, only in the summertime.