crazy like a fox vs feigned

crazy like a fox

adj
  • Behaving in a foolish, frivolous, or uncomprehending manner as a ruse for concealing clever deeds or deeper intentions. 

feigned

adj
  • Being a pretense, a counterfeit, or something false or fraudulent. 

How often have the words crazy like a fox and feigned occurred in a corpus of books? (source: Google Ngram Viewer )