My sister is currently living in a home and has noticed dark stains
appearing on many of the ceilings/wall (particularly at the
The house is heated by forced hot water. The furnace burns natural
gas. It is a 1 level house. Some candles are burned (tea lights,
scented candles). She states that maybe twice a week she uses candles
but for a relatively short amount of time.
Many of the stains are in rooms that do not have candles burning.