snare vs will o' the wisp

snare

noun
  • A mental or psychological trap. 

  • A trap (especially one made from a loop of wire, string, or leather). 

  • A set of stiff wires held under tension against the lower skin of a drum to create a rattling sound. 

  • A similar looped instrument formerly used to remove tumours etc. 

  • A snare drum. 

  • A loop of cord used in obstetric cases, to hold or to pull a fetus from the mother animal. 

verb
  • To catch or hold, especially with a loop. 

  • To ensnare. 

will o' the wisp

noun
  • A delusionary or otherwise unachievable goal that one feels compelled to pursue. 

  • A flickering light or lantern, especially over bogs, swamps or marshes, held by a supernatural creature who uses it to lure travelers at night to their demise. 

How often have the words snare and will o' the wisp occurred in a corpus of books? (source: Google Ngram Viewer )