Our shower on the main floor seems to be leaking into the basement. It is not the tub or the drain, the floor boards are not wet. The cold water faucet leaks bad into the bathtub when it is on. Could it also be leaking behind the drywall too? The water is making puddles in the basement when we take showers? Would we have to have the drywall ripped out and have a plumber replace the whole works or could it be simple? Any advice is appreciated because we cannot sell our home with a leaky shower faucet.