If you wire 10 or 18VAc to the RB/RG leads (where your 118 is wired) and put buzzers in the phone and connect that pair to the RG/RC leads, you'll get buzzers buzzing on incoming ring.

A relay or switch could switch the proper ringing current onto the RB/RG leads while simultaneously switching the buzzer/ringer pairs onto RG/RC.

Sam


"Where are we going and why are we in this hand basket?"