This is a replacement doorbell.It has a separate plinth that can be printed in a different colour. The button can be printed in clear and illuminated if preferred. The switch action is provided by two tactile switches (like these http://media.rs-online.com/t_large/F7581938-01.jpg) soldered to a small piece of stripboard that is held by the backplate. The switches are in parallel and closing either one will sound the bell. I also included a small spring between the stripboard and rear of the button, and a 3mm LED, on mine.
Heavily modified Prusa i3 derivativesteel
I used ABS but PLA should work just as well. No rafts or supports needed if you get the orientation right.