Shaft

Can you provide the whole sentence please? Do you mean "an electricity shaft"?

'A bolt is a shaft of electricity'

A bolt of lightning might be described as a shaft of "pure" electricity.
("shaft" as in "a shaft of wheat")

Large highrise buildings have electrical conduits in which "shaft" could be used in the sense of an elevator shaft, but they're usually called "wireways."

Back when the US used to manufacture things, a "shaft" was a stout metal rod, or bar, called a "drive shaft."

i think that in his sentence it means that the bolt which is an electric bolt i assume is just a thing made out of pure electricity.

Yes. I think it would have to be visible, as in the spark plug of a car - but probably much larger, to be called a "bolt."

Perhaps something off a Van De Graaff generator.