excite vs light a fire under

excite

verb
  • To arouse or bring out (e.g. feelings); to stimulate. 

  • To cause an electron to move to a higher than normal state; to promote an electron to an outer level. 

  • To energize (an electromagnet); to produce a magnetic field in. 

  • To stir the emotions of. 

light a fire under

verb
  • To motivate or encourage (someone) to start sooner or move faster. 

How often have the words excite and light a fire under occurred in a corpus of books? (source: Google Ngram Viewer )