This Old House
The videos from This Old House here are mostly about working in older houses, where the wiring and plumbing do not always match what a new-construction video assumes. They cover replacing a shower cartridge in a 1964 valve, a light fixture on 1960s wire, a smart thermostat on two-wire cable, and installing a dishwasher.
There are bigger builds too: a two-level deck with ipe boards and a dovetail railing, and running power to a shed. Several videos explain why something is done, such as how a GFCI senses a small leak or why reverse polarity matters. Electrical work should follow the breaker-off, test-first routine in our safety guide, and anything near a panel belongs to a licensed electrician. Browse the full set under Electrical and Plumbing.