Leviticus 14:33-42

Then the LORD said to Moses and Aaron, “When you arrive in Canaan, the land I am giving you as your own possession, I may contaminate some of the houses in your land with mildew. The owner of such a house must then go to the priest and say, ‘It appears that my house has some kind of mildew.’ Before the priest goes in to inspect the house, he must have the house emptied so nothing inside will be pronounced ceremonially unclean. Then the priest will go in and examine the mildew on the walls. If he finds greenish or reddish streaks and the contamination appears to go deeper than the wall’s surface, the priest will step outside the door and put the house in quarantine for seven days. On the seventh day the priest must return for another inspection. If he finds that the mildew on the walls of the house has spread, the priest must order that the stones from those areas be removed. The contaminated material will then be taken outside the town to an area designated as ceremonially unclean. Next the inside walls of the entire house must be scraped thoroughly and the scrapings dumped in the unclean place outside the town. Other stones will be brought in to replace the ones that were removed, and the walls will be replastered.