I would have to agree that the smell of cigarette smoke lingers. My family is non-smoking and we have lived here almost 4 years. To my knowledge the previous owner of the home never smoked, but when I walk by my one daughters' room it almost always smells of smoke. We had such a quick tour of the home that I didn't notice it until we took possession. It is just one room but I think the previous owner designated that room as the 'smoke' room.

I also know that smells in a home daycare can sometimes be misleading! I had family come for an interview who swore that a certain area of my daycare smelled 'perfumy'. After some investigation, I discovered that it wasn't originating from my home but one of my daycare children's snowsuit, I asked the mom the following day about the smell, and she informed me she wanted the snowsuit to be soft so she washed it with double the fabric softener. My daycare smelled like the snowsuit for a good week. I was thankful that it wasn't a 'bad' smell

I guess my point is, if it is the whole house I would have to question whether someone smokes in the home daycare area, but if it is in a specific area the smell might be from the daycare children's items.