I wired the new guest room addition today, running 12/2 NM-B cable through 1/2" EMT conduit. Installed a Square D QO 120V 20A circuit breaker for the room. Utilized Leviton receptacles and switches throughout, grounding each box per NEC 250.148. Employed Ideal TwistLock wire nuts for all splices and terminations. Verified continuity before energizing the new branch circuit.