Door Bell wiring

[Tony297]

I have an old Friedland Door Bell. It is transformer powered and works. But the cover was broken some time ago. I now want to re-decorate and it looks a mess. Friedland tell me that they cannot supply a spare, as they were taken over, shut thier factory and changed thier range! Does anybody know where such a thing could be obtained ?
Alternativly I could replace the Bell, but I am confused by the wiring. There are four wires in the bell box. Three are screwed to terminals and one is floating about. Can anybody shed any light on how this is wired up and will I be able to easily connect a new bell if thats the route I have to go down.

Thanks for any help. Tony

 

[breezer]

it would be cheaper to get a new door bell, as it will be less hassle.
i assume you are saying the 4th wire is connected to nothing?, if this is the case and your door bell works, make a note of which wire goes where, mark each one as they are probably all white put the new bell up and connect in the same place