wireman vs wirer

wireman

noun
  • Someone who works with wire; primarily someone who connects electric wiring. 

  • A person who sets up electronic surveillance. 

wirer

noun
  • A person who installs wiring. 

  • One who sets a wire, or snare. 

  • A tool to assist in installing wire. 

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