What was found
WHILE ON APPROACH INTO BTV, PILOT SELECTED GEAR DOWN AND NOTICED THAT THE INTRANSIT LIGHT REMAINED ON AND THE NOSE WHEEL LIGHT STAYED OFF. PILOT RECYCLED GEAR SEVERAL TIMES WITH NO CHANGE. PILOT PERFORMED EMERGENCY GEAR EXTENSION CHECKLIST AND PUMPED GEAR DOWN. AFTER THIS PROCEDURE WAS PERFORMED THERE WAS NO CHANGE IN THE LIGHTS. PILOT DECLARED EMERGENCY AND LANDED WITHOUT FURTHER INCIDENT. AIRCRAFT WAS TOWED TO THE MAINTENANCE FACILITY AFTER VERIFYING THE GEAR WAS INDEED DOWN AND LOCKED. MAINTENANCE INSPECTED SYSTEM AND FOUND NOSE GEAR DOWNLOCK SWITCH PACKED WITH ICE AND SNOW. CLEANED ICE AND SNOW FROM SWITCH. OPS CHECK OF GEAR INDICATION NORMAL PER APPROPRIATE MANUAL. AIRCRAFT RETURNED TO SERVICE.