Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor; Flight Crew Multiengine; Flight Crew Instrument
Flight Crew Last 90 Days 300; Flight Crew Total 16500; Flight Crew Type 50
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Clearance; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Flight Crew Diverted; Flight Crew Landed in Emergency Condition
Aircraft
Smoke in cockpit at FL 190 caused by wiring ground in pilots yoke.  Notified ATC authority and initiated emergency descent.  Diverted into ZZZ. ARTCC aided with initial vectors.  Arrival and landing normal.  Smoke cleared after circuit breakers popped.  Repair made next day by Company 1; and cleared for flight.
Pilot flying Cessna 421 aircraft reports smoke in cockpit and makes emergency landing.