Leviticus 14:37 (KJV)

And he that owneth the house shall come and tell the priest, saying, It seemeth to me there is as it were a plague in the house:

Then the priest shall command that they empty the house, before the priest go into it to see the plague, that all that is in the house be not made unclean: and afterward the priest shall go in to see the house:

And he shall look on the plague, and, behold, if the plague be in the walls of the house with hollow strakes, greenish or reddish, which in sight are lower than the wall;

Then the priest shall go out of the house to the door of the house, and shut up the house seven days:

And the priest shall come again the seventh day, and shall look: and, behold, if the plague be spread in the walls of the house;