As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHEN BASE OF GRIMES LT TOUCHES FOOT SHOULDER HEATER SWITCH SPARKS ARE EMITTED. BOTH CAPT AND F/O SIDE. PULLED CB P-32 TO DEACTIVATE ALL GRIMES LTS FWD TO MCO AND PLACARD PER MEL 33-11-01. DISCONNECTED F/O LIGHT ASSY FRM TERMINAL STRIP FOR CIRCUIT ISOLATION. RECONNECTED F/O LIGHT ASSY TO TERMINAL STRIP. FO WIRES AT TB5100 5102 5104 SWAPPED. REWIRED PER W/D CKS GOOD PER MM. MCO/PLACARD REMOVED.