As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE VACUUMING WITH THE LEFT BATTERY "ON", A STRONG ACRID ELECTRICAL BURNING ODOR WAS COMING FROM THE REAR OF THE CABIN. FOUND THE STATIC INVERTER MAKING A BUZZING SOUND AND GIVING A BURNING ODOR. R & R THE STATIC INVERTER. OPS CHECKED GOOD IAW MM 24-20.