callbox

/K AO1 L B AA0 K S/
noun
  1. 1

    A box containing a telephone for use in emergency, usually mounted on a post in an area where normal access to telephones is inconvenient (such as on an interstate highway or a very long highway bridge).

  2. 2

    A telephone box.

  3. 3

    The wall-mounted box allowing a person to speak into an intercom.

Source: https://en.wiktionary.org/wiki/call%20box, https://en.wiktionary.org/wiki/callbox