TV Land has been running old episodes of the show "Benson". In one episode, they received a telegram announcing an award winner.
I was surprised they'd still use mention of a telegram that late; by then telegrams were virtually obsolete. For the scene's dramatic effect, it was necessary to have the message in a sealed envelope and be something special as opposed to the regular mail.
As an aside, in an I Love Lucy episode, Lucy received a telegram from a fancy women's group she sought to join. That was interesting since it was a local group and I'd think a plain letter or phone call would do. I wouldn't think telegrams would be used for local in-city messages after the war, but maybe they were.)
In a current TV show, The Suite Life comedy, a sci-fi machine was built that looked like a British payphone booth. The stars of the show (13 y/o boys) remarked that "no uses pay phones anymore". (Actually the machine shifted to parallel universes and the subsequent plot was similar to the old Star Trek episode "MIrror Mirror".)
I just realized that this show's scenes makes use of today's instant communication that would be unheard of in past TV. They had one scene where they put together a commercial for the owner of the hotel where they live. The owner, in a very distant overseas city, saw the commercial instantly and phoned at once to voice his opinion; the call was instantly received on his daughter's cell phone. However, some scenes still rely on relayed messages or even newspaper headlines (an old movie trick) to convey information for dramatic effect.
In I Love Lucy there were no cell phones, of course, but Lucy seemed to be always near a phone when she needed it; she often used her apt phone and called Ricky at work. I do believe there were plots where she couldn't reach Ricky and concocted a scheme as a result. That's all doable today, they just have to make the excuse a cell phone was turned off.
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