Make sure it's not too general, please!
I love seeing movies where an apartment/house previously seen as inhabited turns out to look completely different without the implication of someone freshly moving out or be completely abadonned for too long to had looked like this at the time of previous insepction.
Movie I know of where it has happened
They Cloned Tyrone had this happen and I loved it so much.
I think I remember seeing this trope at least twice in some horror movies, but I don't remember their titles. It always gets my attention.
Plumbing can be intense at times. Water is kinda like fire and there's potential for very expensive damages.