Skyhawk 172/Cutlass 172
Flight Crew Instrument; Flight Crew Flight Instructor; Flight Crew Commercial
Flight Crew Last 90 Days 60; Flight Crew Total 450; Flight Crew Type 450
Conflict NMAC
Flight Crew Took Evasive Action
Aircraft; Human Factors
While nearing the final approach fix into ZZZ on the ILS XXR we were alerted by ZZZ Tower of an aircraft that was not on frequency with Tower flying at our altitude at night. We didn't make visual contact with the aircraft until they were very close and passed just below and behind us. Looked to be not more than 100 ft. or so. This was well over an hour past sunset and quite dark.Were told that ZZZ Center had a Controller watching the aircraft in question and were going to see where they landed and get in contact with the Pilot. I would like to be contacted that the Pilot in question was found and notified of what happened.
GA pilot reported an NMAC with an aircraft that was not on frequency with Tower.