Electrical, I called my FIL who is an electrical engineer and is a firm believer in doing it yourself rather than paying someone. He talked me through wiring a brand new light, replacing an entire outlet that had gone bad, showed me how to run new outlets and new light and how they would hook into the breaker box. He also picked up plumbing from somewhere and talked me through some of that. My dad had to rewire the box that ran from the electric company's lines to the house lines to be up to code before the electric company would replace a broken wire.
I was good with numbers and budgeting a check book and had an office procedures course in high school so my new husband who worked in construction supply talked to his boss who talked to one of the subcontractors and I got a bookkeeping job. He wanted to get a class A contractor's license than he had, dragged me along to the course, and then about 20 minutes into the course he got a phone call and had to leave and told me to stay and take really good notes so I could brief him before the test. I regurgitated the information well enough that he got that license, so definitely picked up a lot of stuff about carpentry there. Add in that a couple of my husband's friends were framers, and they walked us all through the practical side when we were building stuff for sci fi/fantasy conventions. One also showed the ropes in repairing a leak in the roof of the house that we were at. Also part of that bookkeeping, I learned a lot of codes and where to find out how to meet them. My husband working in construction supply, he made sure I learned how to use power tools because he thought they were cool as shit. Oh, and everything we install in the house has to have heavy duty fasteners, so I had to learn how to properly use them.
Same FIL, he rode our asses hard to repair our own dryer and our own washer when they both broke. He also showed how he ripped out a fireplace and ran piping lines in its place for a water heater, and then capped that off and walked me through doing it, because we were seriously considering ripping out a cabinet and putting in a dishwasher and we would need to lay the lines in. Alas, the space sizing didn't work, but I got enough of the basics down and again, that framer bookkeeping job taught me where to go for information and who to talk to for help when that information falls short.
At this point in life, when family or friends need something fixed, fingers get pointed at me. It's been a few years since I was taking a saw to wood, but the memory is there, the math is most certainly still there, and how to find what I don't know and follow those directions is still there, and I love using hand tools.
Sure, I'm not a master electrician or master plumber. But the qualifications that I saw for PMT didn't call for either. I'm sure a lot of it is OJT, not a host of degrees and certifications before Target hires. I'm also sure that the pay rate for trained electricians and plumbers is far higher than what Target offers a PMT. Back in the day I felt that if I wanted to deal with miserable outdoor working conditions and some degree of harassment from construction workers of the male persuasion I could have done well in pursuing an electrician apprenticeship and the local shipyard was always hiring, but outdoor, yuck.
Knowledge and practice is not limited to formal schooling. A lot of knowledge comes from being creative with what education you do have and seeking opportunities to practice what you learn. I hate the teeny backwater village that I'm currently in as there are just no jobs in my field ever posted on job hiring sites within the radius I can commute, I hate that my husband was transferred to this teeny backwater village, and I hate that I had to leave a very nice job that paid incredibly well and had me on the track to working in the escrow department, which would have opened the doors to some really, really well paying bank jobs, that I got simply by taking an office procedures class in high school and applying it creatively later in life.