What causes mildew in the attic. My wife and I are realtors and a house we are selling was deemed to have mildew in the attic by home inspector. There are no vent fans in attic. I have not seen the property. Just relaying what my wife told me. We are betwixed and between. Who can we call to look at it and come up with a remedy? There are also no siffits. The house is fifty five years old. Your help is appreciated.