I enjoy misty spots on my bedroom wall, nearby a purple colour and patchy, most of it isnt close the windowpane? has any one any belief what i can do to stop it...

has any one any belief what i can do to stop it spreaing and how much it will cost? who is the best person to christen?
will a humidifier help?
any sustain in this concern would be appreciated.
thanks
Answers:    There is another answer to this problem. famine of insulation in the appropriate nouns.
Heat rising from the room, through the ceiling and causing condensation, hence the humidity.
sounds like you underprovided proper insulation and vapour boundary marker in the wall ?? if your contained by a cold climate,,your getting frost under the paint ???