Are the walls sheetrock? If so, the green has most likely penetrated deep into it. Do you live in a high humidity area? How long has the house not been lived in? Bleach water works well on many things, not sure about inside walls. There are paints with mildew prevention stuff in them. Might be better off replacing the walls as extensive as the green looks. Are there roof leaks?

Omg. Serious stuff. Mold? Mildew? Paint won’t fix it. You have to find the source of the moisture FIRST, stop the moisture, remove damaged materials, replace with untainted materials, then paint.

I would certainly hope no one is living in that house. That is absolutely awful.

Holy S**T.

My thoughts are that this is a hoax post. This looks to be an abandon house, and obviously is not livable.