Leviticus 14

“When you have come into the land of Canaan, which I give you as a possession, and I put the leprous plague in a house in the land of your possession...And the priest shall come again on the seventh day and look; and indeed if the plague has spread on the walls of the house,  then the priest shall command that they take away the stones in which is the plague, and they shall cast them into an unclean place outside the city.  And he shall cause the house to be scraped inside, all around, and the dust that they scrape off they shall pour out in an unclean place outside the city.  Then they shall take other stones and put them in the place of those stones, and he shall take other mortar and plaster the house."  vv.34, 39-42

Read chapter 14.
Leprosy in a house seems strange.  Yet leprosy in the scripture isn't what we think of as leprosy today.  It's hard to tell what exactly this is but from verse 39 we know that this leprous plague is from the Lord.  This wasn't because the owner didn't keep his house clean but a supernatural plague.  Most likely God would do this because of sin of the owner of the home.  At this point in time the Israelites were still traveling and living in tents so this wasn't something that was happening yet but when they settled in the land of Canaan and built their homes.  
I like the metaphor that can be taken from the house being our body.  It starts with the priest examining the house and finds leprosy, comes back seven days later and has spread all over the walls, so the house is to be scraped out and replace with new stones, mortar and plaster.  So sin in our lives, a little sin can spread fast and corrupt the whole body.  When getting sin out it may hurt as if being scraped with a sharp chisel but then not just being left empty holes in the house or in our hearts but replacing it with good.  What "leprosy" do you have in your "house"?