I have a Kohler cast iron tub with wet bed tile on the walls. The tub has been caulked recently & looks good. Sometimes when i take a shower i get a small leak in the kitchen ceiling below. I looked in thru the access panel behind the tub with a drop light. I could'nt see anywhere the water could of came from. I even felt around & nothing is wet. This only happens maybe once every couple weeks. How can it only leak ocassionally ? I want to paint the damaged ceiling,but can't untill i find the source of the leak. Any suggestions appreciated.