What was found
AS PILOT STARTED DESCENT, CREW NOTICED STRONG SMOKE ODOR IN COCKPIT; FIRST ODOR WAS "CHEMICAL ODOR" WHICH QUICKLY BECAME "ELECTRICAL" IN NATURE. AS CREW LOOKED OUTSIDE TO CHECK FOR AN OUTSIDE SOURCE, PILOT CHECKED INSTRUMENTS & CAUTION LIGHT PANEL WITH NOTHING NOTED. CREW ANNOUNCED THAT THEY COULD SEE SMOKE COMING FROM BEHIND INSTRUMENT PANEL ON LT SIDE OF ACFT, PILOT COULD DETECT BUT NOT SEE SMOKE. LANDING AND SHUTDOWN UNEVENTFUL, & SUBSEQUENT POST FLT INSPECTION REVEALED NO EVIDENT DAMAGE. MECHANIC COULD FIND NO EVIDENCE OF FIRE/SHORT CIRCUITING IN ELECTRICAL SYS, AND ON ACFT COULD NOT RECREATE ANY ODOR, SMOKE, OR SYSTEM INDICATIONS OF FIRE. ACFT WAS RETURNED TO SERVICE.