The contact owns a 2014 Chevrolet Silverado 1500. The contact stated that the headliner above the rear window had water stains. The contact stated that as a mechanic, he had inspected the vehicle and diagnosed that the water was leaking from the third brake light. The contact stated that the gasket surrounding the third brake light was no longer properly sealing the third brake light. The dealer was notified of the failure and informed the contact that the VIN was not included in an unknown recall. The vehicle was not repaired. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 72,000.