For the record:
My college roomate and I were sitting in the back row of a movie theatre, and the movie had been running for about 5 minutes.
Between our seats, was a new metal conduit that exited the wall behind our seats, about 20 inches above our heads . . . and ran up to . . . and then entered the wall, very near the portal window where one of the theatre’ cameras was located.
We both heard a sharp pop, looked up the conduit and wall . . . and about 5 ft above, flame erupted from a conduit joint while smoke erupted from another joint were the conduit entered the wall near the camera.
We stood up, I made a loud whistle and in my best [military] commanding voice:
LADIES AND GENTLEMENT, THE THEATRE HAS A FIRE. PLEASE DO NOT PANIC, BUT PLEASE IMMEDIATELY LEAVE THE THEATRE.
My roommate stayed, helping people, while I moved quickly to alert the manager and call the fire department.
People left the theatre in an orderly fashion - no panic.
Fascinating!