John Cartmell wrote:
My daughter has recently moved into a 1930s semi and, after a few
weeks, is finding that one of the bedrooms smells strongly of tobacco
smoke in the mornings. No one in the house smokes and it's presumed
that it's coming from next door.
Obvious possibilities a
through the window - unlikely?
through blocked up flue;
through hidden air vent
?

Other possibilities to investigate or suggestions for treatment would
be appreciated as the bedroom in question is granddaughters (12
months) and she has been sleeping badly recently (?connection?) and
I'd like to help get it sorted pdq.

The house might have caught fire at sometime before she bought it, and the
walls might have just been painted over?