Usually in the cistern of the toilet in an actuator of a shutoff valve on the lever set hollow plastic float. If its integrity is violated, it fills with water and stops working. As a consequence, continuous noise of flowing water, condensed moisture on the tank, dampness and mold.
Radically and just to correct the situation will help a stick of foam, which you must impose on the lever instead of the float.
Recommend to read
A CIRCLE WITH A RULER
Any of the compass there is a limit in describing them circles. However, a circle of the desired radius can be obtained using... line. Just drill in it a large number of holes, then the...
THE SLED WITH RUBBER BAND
That the cord does not interfere with the movement of the sled during the descent from the mountain, I propose to make it retractable. For this to end you need to tie the two segments of...