fire alarm vs wake-up call

fire alarm

noun
  • The sound or other warning made by a fire alarm. 

  • An electromechanical or electronic bell, klaxon, chime, horn, speaker, strobe light or other device which warns people in a building of a possible fire or other condition requiring evacuation. 

  • An emergency response to a fire by the fire department with manpower and equipment. 

wake-up call

noun
  • An alert, reminder, or call to action caused by a dramatic event. 

  • A telephone call to awaken someone at a certain time, especially one requested by the person while staying at a hotel. 

How often have the words fire alarm and wake-up call occurred in a corpus of books? (source: Google Ngram Viewer )