imagine waking up in a coffin and realizing that you were mistakenly buried alive now this wouldn't happen with the medical guidelines we have today but in the 19th century old coffins were found with scratch marks on the inside making this a legitimate concern so as a solution they started adding strings inside the coffins that traveled up to the ground and were connected to a little bell and if you woke up under ground in a coffin you could just ring the bell signaling that you're still alive