Upon arrival I was able to determine that customers 1/2 hot copper water line coming from water feeding the manifold located behind the shower that is leaking. Recommended performing a re route as we have been doing for the other units. Performed re route to the half inch copper water line that was leaking. Re routed new line from water heater over to the manifold behind shower. Upon opening drywall behind water heater we saw that customer had some electrical that appeared to have been damaged due to either mice chewing on it or from when the electrical was ran. Notified management of the issue.