Basic plumbing skills. How to unclog a toilet properly, how to shut off the water to a faucet, or the building.

Home maintenance 200.

How to do basic drain clogs with a plastic drain reamer. Also, how to use a drain snake and snake out a clogged bathtub via taking out the hardware for the tub stopper.

How to rebuild a toilet via installing a new flapper, fill kit, and how to check for leaks. How to take off the trap on a sink drain and fish out a lost ring.

Not really complicated, takes some knowledge, but mostly practice. I don't see why any high school kid can't be able to handle some basic plumbing.

How to flip breakers in an electric panel so if you lose power to an outlet you can flip it back on.

Also, how to reset a GFCI outlet. Not complicated, but, you'll feel stupid if you pay a service call for a guy to show up for 75$ to push two buttons. Installing a new single pole switch, outlet, or GFCI. Sure, let an electrician do it, but, some people prefer to be thrifty and save money.

I guess I would run an advanced basic home repair course and teach people how to patch some drywall, reset garbage disposals, do some really basic HVAC repairs and maintenance.

It's preferred to have a licensed, bonded, insured, professional do the job... but... sometimes it's 3am and it's 10 degrees outside and your furnace won't blow heat and the house temp has dropped to 58... so you goggle how to fix it and realize you need to take the panel off, suck and blow some air into the pressure switch, and voila you have heat again when at best the repair guy can get to you sometime within 24hrs. Granted it is not always the pressure switch, nor is it always that easy ( took me 3 or 4 tries last time).

Or knowing how to shut off water. Imagine something weird happens and water is spraying everywhere. If you know how to shut off the water, you can minimize damage, or if you are unable to do so, face the fact that water damage is expensive and snowballs into bigger problems like mold in places you can't see.