Leviticus, Chapter 14, verses 33-53
When Mildew Is in a House
33The LORD told Moses and Aaron to say to the people:
34After I have given you the land of Canaan as your permanent possession, here is what you must do, if I ever put mildew on the walls of any of your homes.
35First, you must say to a priest, “I think mildew is on the wall of my house.”
36The priest will reply, “Empty the house before I inspect it, or else everything in it will be unclean.”
37If the priest discovers greenish or reddish spots that go deeper that the surface of the walls, 38he will have the house closed for seven days. 39Then he will return and check to see if the mildew has spread. 40-41If so, he will have someone scrape the plaster from the walls, remove the filthy stones, then haul everything off and dump it in an unclean place outside the town. 42Afterwards the wall must be repaired with new stones and fresh plaster.
43If the mildew appears a second time, 44the priest will come and say, “this house is unclean. It’s covered with mildew that can’t be removed.” 45Then he will have the house torn down and every bit of wood, stone, and plaster hauled off to an unclean place outside the town. 46Meanwhile, if any of you enter the house while it was closed, you will be unclean until evening. 47And if you either slept or ate in the house, you must wash your clothes.
48On the other hand, if the priest discovers that mildew hasn’t reappeared after the house was newly plastered, he will say, “This house is clean – the mildew has gone.” 49Then, to show that the house is now clean, he will get two birds, a stick of cedar wood, a piece of red yarn, and a branch from a hyssop plant and bring them to the house. 50He will kill one of the birds over a clay pot of spring water 51-52and let its blood drain into the pot. Then he will dip the cedar, the hyssop, the yarn, and the other bird into the mixture of blood and water. Next, he will sprinkle the house seven times with the mixture, then the house will be completely clean. 53Finally, he will release the bird and let it fly away, ending the ceremony for purifying the house.
*Source – The Bible (New International Version)