Sounds like Shenzhen signboards during the previous mayor era. Something akin these lines:

"Punishment for public defecation: first prosecution - struggle session; second prosecution - reeducation through labour; third prosecution - jail"

Or hilarious tablets in the metro back in days: "Beware of the gap, you will loose your footing and break your face if you stumble", and the famous "Decapitation hazard" - on escalators