Dude.... sounds like my house.
We knew it would need SOME work cuz it was leased out as section 8 for awhile and had not had a tenant for at least a year or two before we moved in, but holy carp terds!
Someone please explain to me how the best way to secure a window mount AC unit is to put six inch lag bolts through the second story window frame at the bottom with no caulk. Please.
Just from that maneuver, we had to rip out, spray down, paint, and replace the whole ceiling in the utility hall, 3/4 of the walls in that hallway, all the molding, two light fixtures and part of the floor. It was all infested with mold and falling out, plus there was a lovely ant colony in the base of the wall cuz of the moisture.
And that doesn't begin to cover the problems we found in the kitchen whilst fixing that hall. Let's just say we had it down to studs and sub floor for about two weeks...