mold on wall

TCPPC

Hi I just had my bedroom paint and I left it dry for a few days but one of the wall have small dot damp but we didn't have it before.

could it be the wall was not well ventilated to dry which cause the problem?

cyclonebri1

Possibly, equally likely that a food spot/splash has been re-activated and mold has formed owing to the water content in the paint.

Rub it off and ventilate, always a good idea to leave windows on the latch for a few days after painting anyways. A rub down with sugar soap or even a knock over with abrasive paper helps avoid to.

Sorry, just re-read your post, the advice above still stands for it may not be mold, but the damp spot could indeed be food grease showing through.

Edited;

Just re-re-read as you said mold in the tile and damp in the tread itself, my views apply to either situation.