What could cause black smokey walls and ceilings in a house?

I was wondering if what cause black/grey smokey walls in a house? The walls look dirty but not like there has been a fire and no sign of a fire in the home at all. It's a light black color dusted on the walls and ceilings. There is a fire place but it's propane unless they maybe used it as a regular one at one time...? Could this be from a smoker? We are trying to figure it out but can't get the records on the house because it's a foreclosure.|||You ARE going to have a home inspection, right?





The inspector will be the one to ask, not here.|||If it was a smoker the walls would have a yellow tint not black. If the flu on the fire place is stopped up or the flame is to high then it could cause sooting you need to get this checked out . Carbon dioxide gas is undetectable as far as smell if it is sooting a certified tech should be able to correct the problem in no time. Or if the house is damp it could be mold . Which could cause allergies and sickness. Anyway good luck and Merry Christmas.|||The furnace could be faulty. Could have been a fire even if you don't see obviously charred wood etc. Usually smoker stains are yellowish. Ask your insurance agent to run a CLUE report on the address and see if there have been any claims filed for the past 3-5 years as that may shed some light on it too.|||if it is in corners or where ceiling meets the wall it could be something called black mold-use bleach water to clean it off and if it re-occurs you may have a mold problem -god bless|||The furnace could need to be clean my was doing this and I had white furniture. Or you could need to replace your furnace which is about 2500. In my old house this is what happen.|||It is probably from a hole in the heat exchanger on the furnace.It needs to be replaced as it could be fatal.|||Oil heat has been known to cause some soot accumulation on the walls.|||is the furnace a fuel oil furnace?


if so that's the culprit its falty