Doorbell – sound mechanism
Installation of a doorbell in an apartment : Doorbell Sound Mechanism
Quote from Article entitled Installation of a doorbell in an apartment:
As a rule, the place of installation is located in the corridor or the hallway. Radiators or other heating devices should not be in the radius of one and a half meters from the device. In the place of installation a hole is made in a wall, by a drill and the panel of the sound mechanism is fastened with wall dowels and screws. All manufacturers of the devices make hidden holes for fastening. In the door frame a hole is drilled for connection of the sound panel and the button by wires.
The full version of the article can be found here.