A smoke detector in every bedroom and a smoke detector and carbon monitor in hallway of every floor and in the basement or attic IF you have furnace, hot water heater etc in them.

I have seen doors swing wide open and shadowy-figures emerging from the darkness.

So, you add a rule with 30 days notice that there is no smoking on the premises at all!

We figure he must’ve been smoking a cigarette. 

You can try free sites like Spokeo as a shot in the dark, but it's not too hard to find the owner's information if you are good on the internet.

Case in point: LA city... and most recently, in the dark of night without warning, Pomona.I know there will be some on this forum who may disagree and will have their personal stories of how to overcome it and work around it.

Lol someone says they're not interested in jumping through hoops means they're not serious or their buyer is all smoke no fire. 

Some years smoke detectors need to be in bedrooms, others not.  

I had all new smoke detectors with 10 year batteries put in, so I wouldn't have to worry about changing dead batteries - that beeping can ruin a guest's vacation. 

I give her a little key advice to smoke them out.