At first, this looked more like household appliances than the real category. The opening clues stay ambiguous until Television schedules gives the board a cleaner test, so this guide starts with the misleading first read, then uses the later clues to show why the final connection is narrower than the early guesses and how each clue checks that same pattern without relying on the answer reveal too early.
Mailboxes pushed me in that direction immediately.
Toasters kept that theory alive for a moment, but Television schedules still did not quite fit.
That was the moment the first idea stopped working.
Then Television schedules made me stop thinking about household appliances and start thinking about the real category.
Mailboxes fit once I read it through the answer.
Toasters fit once I read it through the answer.
The answer was Things with slots.
Computer motherboards and Vending machines (for coins) then felt less surprising and more like the last pieces falling into place.
Looking back, the answer feels obvious in the best way.