There are plenty of people that want to be electricians - the schools only accept so many applicants. It's the same issue with the artificial doctor shortage - artificially limited supply to keep wages high.
An electrician is doing hands on stuff in a lot of labs. That limits the student to teacher ratio that can be sustained. So, you'd need a lot more teachers who are already certified as electricians to come teach. Are you paying them enough to get them to come teach as opposed to work or manage? (LOL--teachers always get paid absolute dogshit).
After your first year of training, the expectation is that the apprentice is getting paid. So, you need to have some companies willing to cough up to pay more for the increased number of apprentices. Who is incentivized to do that?
Want more electricians? Bump the pay to $100K/year for a journeyman. You'll have lots of people wanting to be electricians.