switchboard vs wall socket

switchboard

noun
  • A large piece of power-distribution equipment that directs electricity to multiple loads. 

  • The electronic panel that is used to direct telephone calls to the desired recipient. 

wall socket

noun
  • A mains electricity power point mounted in or on a wall inside a dwelling or other building. 

  • Any outlet or recess in a wall. 

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