It's also weird to single out electricians when it's the construction companies themselves that are being dragged across the globe to the few places that will auto stamp new data centers. There's a private compound in the Western US that doesn't allow reporters and is blowing millions to bring workers in from thousand of miles away. Rumor is local crews weren't considered because they'd be more likely to report environmental concerns in their own backyard.

Well yeah, it’s right there in the first sentence

Electricians are getting harder to find, and some construction projects are on hold.

They’re talking about commercial electricians. Because of all these data centers being built electricians are being moved around because of the money being thrown at these projects. For example, Dallas has been a hub for tech sector projects for a while; because of all the new data centers being built in Texas there are out of state electricians coming in for these projects from neighboring states like OK. Funny tho, now that Oklahoma is starting its own data center boom, now electricians from OK would just rather stay there which is causing projects in TX to stall.

While you are not wrong about these different specialities within the trade, there can still be an effect. Let me illustrate:

Suppose you like bananas but not apples. One day there is an apple disease that kills most of the apple trees leading to a collapse of the apple market. You feel relieved because you don't eat bananas anyways. But you go to the supermarket and find that not only are the apple shelves empty, the banana shelves are empty too! Why? Well people still gotta eat, and not everyone is as picky as you, they switched to bananas and now the banana market is under supplied too. And it's not like you can build a banana farm overnight.

Back to electricians, if the salaries of data center electricians increases rapidly, you will find that those electricians who are qualified for both (even if it is just a very small number) might focus on data centres, straining the supply of residential electricians. Just like with banana orchards, it takes time for new electricians to enter the market, and those new hires will further be swayed to the data center specialty first, further straining the residential market.

We can see a real example of this with the price of RAM. RAM manufacturers saw increased demand for data centre RAM so they switched focus to that market and it ended up drying out the consumer side supply, hence the surge in price. And just as with banana plantations and electricians, you can't start up a RAM fab overnight.