Bathroom Walls

Thanks for your suggestions on my bathroom wall. I am not sure it is a leak because the dripping light brown goo is on all of the walls starting about a third of the way down. It is and inside room with no windows and there are not pipes on all sides. The ceiling has no damage or discoloration and the walls in the rooms backing up to the bath have no damage. A friend suggested that maybe someone had smoked in the room and that with the humidity from hot showers that was nicotine coming from the walls. I don't know. Bleach, kilns, lots of bathroom cleaners and repainting have not helped. I am really at a loss.