bin/kafka-console-consumer.sh --bootstrap-server localhost:9092 --topic gray_messages.global.report --from-beginning

  bin/kafka-console-producer.sh --bootstrap-server localhost:9092 --topic gray_messages.global.sound_off

and then type your messages. Here's a few you might like (all will need the quotes fixed :/ but some might need further edits)

  * ''{"type": "gray_messages.global.sound_off"}''
  * ''{"type": "gray_messages.directorial.execute_command", "command":"yt-dl", "args":""}''