In an electrical box in the electrical closet, with the breakers. Like any sane setup. Although if you live in North America and you're used to "wired get stap

In an electrical box in the electrical closet, with the breakers. Like any sane setup. Although if you live in North America and you're used to "wired get stapled onto studs and then we put drywall directly on that" the idea that you can have actual cable routes in the wall that you can just run multiple cables through so you can can take them out and put new ones back in as needed is a surprisingly unknown concept.