As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON CLIMB-OUT, CREW NOTICED SMOKE EMANATING FROM ABOVE AND BELOW INSTRUMENT PANEL. ATC WAS NOTIFIED, THE MASTER SWITCH WAS TURNED OFF, AND THEY RETURNED TO DEPARTURE. FIRE/ RESCUE PERSONNEL VERIFIED THERE WAS NO ACTIVE FIRE. THE ACFT WAS TURNED OVER TO MX FOR INSP AND REPAIR. MX PERSONNEL DETERMINED THAT THE PROBLEM WAS WITH THE LANDING LIGHT SWITCH. THE LANDING LIGHT SWITCH WAS REPLACED WITH A CURRENT PART NUMBERED SWITCH. AN OPS CHECK WAS PERFORMED WITH NO DIFFICULTIES NOTED.