I'm kinda stupid. I've seen these but they always show pictures within the distribution box. Here only certified electricians are allowed to open them. But I totally didn't saw the option to just clamp it on a wire outside the box. I even asked Bing AI for help, because not everyone must sell on Amazon and Google Search just spits out the affiliate link sites, that suggests always the same popular options. 90% of the time switchable plugs.