Around 1940 the light comedy film,"The Major and the Minor" came out.
It appears on TCM from time to time.
In one scene, Ginger Rogers is pretending to be a young girl to get
half fare on the train and finds herself stuck at a military academy
for boys. She needs to get a long distance call out, and the only way
she can is to distract a boy on duty at the school's PBX.
She goes to the PBX and flirts with the boy on switchboard duty. She
gets him to run back to his room to get a radio for dancing, and
offers to mind the board for him while he's gone. She sits down and
places her long distance call. She dials zero, asks for long
distance, then asks for the person by name and address, as was common
in those days. In a bit of dramatic license, she gets through
promptly. While she's talking, calls come through the board, and she
just randomly connects one party to another. Chaos ensues. The boy
returns with a radio, ready to dance, but finds the school
administration has come over to see why calls aren't getting through.