As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE TURNING NR 1 ENG START SWITCH TO START ENG GOT LOUD POP ALONG WITH SPARK FROM BEHIND OVERHEAD PANEL. MTC FOUND 2 BROKEN WIRES BEHIND PANEL THAT CHAFED FROM RUBBING WHISKEY COMPASS EACH TIME IT IS STOWED. REPAIRED WIRES AND REPLACED SWITCH AS PRECAUTION.