danger signal vs notice

danger signal

noun
  • An indication that a potentially bad or dangerous situation could develop. 

  • A signal set at danger and showing a red light or other stop indication, which a train driver must not pass until it changes or until manually cleared past the signal by a dispatcher. 

notice

noun
  • A formal notification or warning. 

  • A published critical review of a play or the like. 

  • A written or printed announcement. 

  • Advance notification of termination of employment, given by an employer to an employee or vice versa. 

  • The act of observing; perception. 

  • Prior notification. 

verb
  • To be noticeable; to show. 

  • To become aware of; to observe. 

How often have the words danger signal and notice occurred in a corpus of books? (source: Google Ngram Viewer )