AC electric motor repair is frequently done these days, typically for generator turbines and the like, whether for power plants or ship and aircraft engines.
Nothing unusual about any of that.
But once upon a time, just a little over a century ago, AC, or alternating current, and DC, or direct current, were quite controversial matters – especially for the two men bitterly locked in what would become recognized to history as the great War of the Currents.

Yes, AC electric motor repair is common enough these days, but back then, AC was new, and originally appeared unsafe – ironic considering that it won out over DC in lots of applications because of its superior safety.
But before this came about, there were the most acrimonious protests, right down to court battles, not to mention personal smearing strategies in the court of public opinion, against AC, the newer technology.

While it’s arguable that the superior AC standard would have finally been adopted, it’s almost certain that the campaign against it, and its most well known proponent, delayed its widespread use for quite a few years.
While something like AC electric motor repair is still rather qualified work, it isn’t the revoluntionary thing it was back when engines running on AC were considered exotic and, as mentioned before, dangerous.

Thomas Edison, the excellent inventor, used AC’s initial faults as a way of personally attacking his one-time assistant Nikola Tesla, another brilliant mind.
Likely due to qualified jealousy (though a lot of money had also been at stake, as numerous patent royalties were included), Edison went to great measures to discredit not only the technology but its most prominent proponent – to the point of macabre demonstrations electrocuting animals and also a condemned prisoner in order to get the public agitated against AC!