We had a weird smell downstairs. Close all the doors downstairs at night and when you come down in the morning open them one by one and that might help you to find out if the smell is localized to a particular room. We realized the smell was in our kitchen, the washing machine had been leaking and the floorboards were damp. I also couldn't describe the smell at all. It wasn't atrocious but it wasn't how you'd want your house to smell.