Where is this wetness coming from? I have discovered tacky in my little boys bedroom. We own lived...

I have discovered tacky in my little boys bedroom. We own lived here for 7 years and there have never been sticky in within before..There is no wetness in any other room
It is a small bedroom at the front of the house.
There are green mouldy patch on the walls that are on the outside of the house, if that makes sence...not on the walls that enrol other rooms in the house..Im sure within is a name for these walls but I am a woman and a bit clueless...
Can anyone back and let me know why this have happened and how i can acquire rid of it. My little boy is only 2 years aged and suffers with his chest anyway so im worried sick..Many appreciation.
Stove inventory and oven won't work but lights...
Answers:    this may sound approaching a daft answer. but it happened to one of my friends. his boy be peeing in the corner every hours of darkness. he was three but it seem that his bed was dry so here no nappies. it was by destiny that he got up within the night to see him almost sleep walking to the corner and have a wee. over the period of give or take a few 3 months this built up.

get s dehumidifier any bearing if this in not the baggage but it may just be
Is the tube plastic?
sounds resembling you have a slick in your guttering or roof tiles above the wall bring back some ladders & check it... the marine could be leaking into the wall cavity short you noticing.