ghost writer vs refuge

ghost writer

refuge

verb
  • To return to a place of shelter. 

noun
  • A state of safety, protection or shelter. 

  • A refuge island. 

  • An expedient to secure protection or defence. 

  • A place providing safety, protection or shelter. 

  • Something or someone turned to for safety or assistance; a recourse or resort. 

How often have the words ghost writer and refuge occurred in a corpus of books? (source: Google Ngram Viewer )