So, this is odd. I have had the same thing happen to me, although since I moved to the new house a couple years ago, it has stopped. In my previous house, I would at night at certain times, usually later in the evening, smell cigarette smoke, very distinct. Neither Julia nor I are smokers. It was strong and seemed to mainly occur in the living room. 

I have not discussed it with many people. Of course, when I did, most people suggested a ghost. A previous resident that smoked. We did own what was said to be a piece of haunted furniture. It was in the upstairs bathroom, far from the living room where I would smell smoke. It was a woman's vanity, a makeup table with a big mirror on it. Julia bought it from some antique store. When it was delivered it smelled heavily of cigarette smoke, so the woman that owned it, I would guess was a heavy smoker. Julia managed after some time to eliminate the cigarette smell. Some people thought the woman that owned the vanity came with it and she would haunt me at night. 

When we moved, we got rid of that vanity. At the new house, we've been here since 2021, I have not been surrounded by cigarette smoke late in the evenings. 

I wondered if I was hallucinating the smoke smell. If I was subject to some form of phantosmia or was it just a phantom, attached to her vanity, wandering downstairs at night and sitting with me. I also have some relatives that have passed that were smokers, so one of them? A former owner of the house that would have a cigarette in the evenings?

For a while I went a bit crazy trying to track down the cigarette smell. It happened in all seasons during the year and Julia was always upstairs asleep. I was always alone when it would happen. So, it was not like it was summer and the windows were open and someone passing outside walking their dog was having a smoke.