If its leaking, that means water is passing the valves in the tap(s) (you might have one of those mixer things that combined hot and cold)

I fixed mine by swapping out the valve. Look like little spinning tops and you can buy packs of em for like $10.

If thats your problem, you can look up how-tos online for replacing valves in taps. Very easy job. Took me ten minutes to do my shower, and thats only because the value was stuck.

Any online guide will warn you to turn off your water supply to your house first. I will remind you also.