Work inside the panel cannot be done safely until water leaking into the panel has ceased and the internal components are dry. Please call us back after an hvac professional has solved this problem. It appears that the air handler is leaking water into the romex jacket and making its way into the panel. There is corrosion damage to two cables. Ultimately these cables will need to be rerun. Left quote for troubleshoot of living-room circuit and replacing AFCI breaker.