Leviticus 14:42

40then the priest shall command that they take out the stones in which is the plague, and cast them into an unclean place outside of the city.

41He shall cause the inside of the house to be scraped all over. They shall pour out the mortar that they scraped off outside of the city into an unclean place.

42They shall take other stones, and put them in the place of those stones; and he shall take other mortar, and shall plaster the house.

43“If the plague comes again, and breaks out in the house after he has taken out the stones, and after he has scraped the house, and after it was plastered,

44then the priest shall come in and look; and behold, if the plague has spread in the house, it is a destructive mildew in the house. It is unclean.