I remember this movie from television perhaps as early as 1970’s where there was a group of bad guys (I think) robbing the rich family there. The son got locked in his room because he was disabled (I think crutches or a wheel chair) and the bad guys thought he would not be able to cause trouble for them. He opens his closet to reveal a ham radio station, with which he contacts people who call the police from all over the world.
I think the story took place in New York, in a high rise building.
The Anderson Tapes starring Sean Connery
From Wikipedia:
Jimmy, the son of two of the residents, is a paraplegic and asthmatic who is left behind in his air-conditioned room. Using his amateur radio equipment, he calls up other radio amateurs, based in other states, who contact the police.