What was found
APPROACHING THE RUNWAY AND DESCENDING TO PATTERN ALTITUDE THE GEAR WAS SELECTED DOWN. 2 GREEN LIGHTS ILLUMINATED FOR THE MAINS AND A RED LIGHT WERE DISPLAYED. WE LEVELED OFF AT PATTERN ALTITUDE AND STAYED IN THE TRAFFIC PATTERN. APPROX 15 SECONDS AFTER THE GEAR WAS SELECTED DOWN, 3 GREEN LIGHTS WERE DISPLAYED. CONTINUED AND LANDED NORMALLY. JACKED ACFT PERFORMED MULTIPLE GEAR SWINGS. ALL CHECKED GOOD. INSPECTED DOWNLOCK SWITCH AND WIRING. ALL CHECKED GOOD. CONTACTED AMCC ADVISED US TO REPLACE SWITCH. R & R DOWNLOCK SWITCH IAW THE MM 32-30-30. OPS CHECKED OK.