We are currently living in a house that was occupied for years by a heavy smoker. She stopped smoking about five years before we moved in, but we’ve noticed that when the bathroom gets steamy the walls and ceiling are dripping with brown water. The same happened in DD’s room when she used a steam facial machine. Short of redecorating, and presumably we would have to make sure the walls were deep cleaned before painting them, is there any way we can get rid of this? The walls don’t look brown; it looks clean and freshly painted. It’s only when it gets wet that it happens.