I suggest Kasa Smart Plugs. No hub required, use a phone app. You set a cadence of on and off times and control manually. App control provides a kill switch capability. Very inexpensive, $20 to $30 for 4 plugs. Obviously, your children could remove the smart plug and just plug the tv into an outlet.

Agree with YoLink. Can transmit very far although hub may need to be in line of sight for applications. I have one on my mailbox door and backyard shed door. You can keep getting alerts if door is left open. Using a water temp sensor for our space. The transmitter failed because of moisture ingress so placed new one in a baggie above insulated cover and under canvas cover. Nice log to see when opened and closed each day. Great customer service as well.

Kasa are pretty quiet. Actually listen for the light click when turning off adjacent hallway lights