He is to examine the house, and if the mildew on the walls consists of green or red depressions that appear to be beneath the surface of the wall,

Leviticus 14:36
The priest must order that the house be cleared before he enters it to examine the mildew, so that nothing in the house will become unclean. After this, the priest shall go in to inspect the house.

Leviticus 14:38
the priest shall go outside the doorway of the house and close it up for seven days.

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;