If you mean an electrical worker like a lineman or industrial electrician, in the early days that was very much a skilled profession- and often a dangerous one.

But if by electrician you mean someone who wires houses ( the commonest electrician now) , in the earliest days of electrification the wiring would really be only for lights, and the "electric bill" was often called "the light bill". As such, the knob-and-tube wiring systems were simple, the installation easily learned. By the 1920's other appliances had been added, and an electrician had to think of more than lights. But not too much more. From one guide to building small houses:

Now, in addition to the lighting of a house, certain floor and base-board outlets must be provided for attaching various electrical devices that have become rather common. In every cellar there should be at least one special power-current outlet for any household machinery that might be installed. In the laundry there should be at least two special outlets to which a washing-machine, a mangle, electric drier, or an electric iron can be connected.

There should be at least one special outlet in the kitchen to which may be attached a motor for operating the coffee-grinder, egg-beater, ice-cream freezer, dish-washer, etc. Sometimes an electric refrigerator may be installed, in which case an outlet must be provided for this motor.

Sometimes a special outlet is installed in pantry for a dish-warmer or water-heater.

In the dining-room a floor outlet should be provided for operating on the table such things as a toaster, chafing-dish, coffee-percolator, egg-boiler, etc.

In the living-room a floor outlet will be found useful for such electric apparatus as would be carried on a tea-table or for running a home stereopticon.

In the bathroom and in the master’s bedroom a special outlet is useful to connect up such devices as vibrators, hair-driers, curling-irons, shaving-mugs, electric heaters, etc.

Base-board outlets of the ordinary type should be distributed throughout the house to provide convenient connections for vacuum cleaners and fans.

So, with perhaps one outlet for each room, and wiring overhead for lighting, any carpenter or handyman could learn to install house wiring. But there were, by the 1920's, Electrical Codes. And so as wiring got more complex and the codes got more rigorous, house wiring got harder to do, became more of a specialty.

Croft, Terrell (1913) The American Electrician's Handbook . McGraw Hill

Walsh, H. Vandervoort (1923) THE CONSTRUCTION OF THE SMALL HOUSE. Charles Scribner's Sons