frightening vs ghoulish

frightening

adj
  • Awful, terrible, very bad. 

  • Causing fear; of capable of causing fear; scary. 

ghoulish

adj
  • Of or pertaining to corpses and graverobbing. 

  • Of or pertaining to ghouls. 

  • Fascinated by corpses. 

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