Nicotine? [Under a black light]

Below is a picture of a black light revealing some sort of smoke residue that was (presumably) left behind by the previous resident on the ceiling of the bathroom. He or she was a smoker and apparently made the bathroom his or her personal smoking room.

In the light, you can see yellow on the ceiling, but the black light really shows how bad it is. When we first moved in, we painted the ceiling, but whatever it is must have seeped through. The patch that isn’t glowing is where I wiped the ceiling with a wet rag.(Click the photo to view a larger version)

If you think you keep a clean house, I invite you to run a good black light through your kitchen and bathroom. Disgusting…