I need help. My mother-in-law just moved into a house (circa 1969-ish) and the smell of mold and mildew is overpowering. We are even beginning to suspect it as a cause for some of her recent illnesses. The problem is that we can't find where it is coming from. The house is built on a slab and we can't locate any leaks or water problems anywhere. Does anyone have any suggestions?