As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT SMELLED UNKNOWN FUMES COMING FROM REAR OF AIRCRAFT. WAS COMING IN TO LAND AT MIAMI VALLEY HOSPITAL AND DIFERTED TO MORAINE AIRPARK (OUR MAINTENANCE HANGAR). UPON INSPECTION I FOUND THE #1 NAV RADIO TO HAVE A BURNT ELECTRICAL SMELL COMING FROM IT. CAPPED AND STOWED WIRES AND MEL'D THE SYSTEM.