Leviticus, the third book of the Old Testament warns us about mildew (mold):
Mildew In Houses
The Lord spoke to Moses and Aaron, "When you come to Canaan that I am going to give to you, mildew may appear in a house. The owner of the house must come and tell the priest that there is something that looks like mildew in his house.
Before the priest examines the house, he will order everything taken out of it so that nothing in the house will become unclean. Then the priest will go inside to examine the house. He will examine the mildew area on the walls. If it is green and red in sunken areas that are deeper than the rest of the wall, the priest will go out to the door of the house and close up the house for seven days.
On the seventh day the priest will go back and examine it again. If the mildew in the walls of the house has spread, the priest must order the stones that have the mildew to be torn out and thrown outside the city in an unclean place. He must have the entire inside of the house scraped. The plaster dust scraped off the walls must be dumped in an unclean place outside the city. The stones must be replaced, and the house must be plastered again. If the mildew develops again in the house after all this, the priest will examine it one more time. If it is a spreading type of mildew, the house is unclean. The house stones, wood, and all plaster must be torn down and taken to an unclean place outside the city. Whoever goes into the house any time it is closed up will be unclean until evening. Whoever sleeps or eats in the house must wash his clothes. But if the priest comes and makes an examination and the mildew has not spread in the house after it is plastered again, the priest must declare the house clean. The mildew is gone.
These are the instructions for any kind of mildew or fungus that infects clothing or houses and for skin diseases where there is a sore, a rash, or an irritated area. These instructions for skin diseases and mildew help you distinguish between what is clean and what is unclean."