string on vs take for a ride

string on

verb
  • To continue to convince (someone) of something untrue; to maintain a lie or scam aimed at (someone). 

take for a ride

verb
  • To deceive someone. 

  • To drive (a person) to a remote location in order to murder them. 

How often have the words string on and take for a ride occurred in a corpus of books? (source: Google Ngram Viewer )