ghoulish vs nightmarish

ghoulish

adj
  • Fascinated by corpses. 

  • Of or pertaining to corpses and graverobbing. 

  • Of or pertaining to ghouls. 

nightmarish

adj
  • Resembling a nightmare. 

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