act of God vs mishap

act of God

noun
  • An unforeseen occurrence beyond one's control, such as a natural disaster. 

  • Used other than figuratively or idiomatically: see act, of, God. 

mishap

noun
  • Evil accident; ill luck; misfortune; mischance. 

  • An accident, mistake, or problem. 

How often have the words act of God and mishap occurred in a corpus of books? (source: Google Ngram Viewer )