I noticed a leak inside our master bedroom closet. The kitchen sink is on the other side of this wall. I pulled up the floorboard and cut out some wet drywall to find an open pipe and found that water trickles from this pipe when the sink is running.
(This closet is connected to the master bath and bedroom. It's part of an extension that was built onto the house several years ago before we purchased it. The house was originally built in the 60's.)
Does anyone know what this pipe is and why it would start leaking?