Dave Plowman (News) explained :
In article ,
Harry Bloomfield wrote:
The only good reason to have a wired system with a transformer, is if
you must have a light on the push. Run on battery they do not last
long. A wired battery one without a light is otherwise fine, but most
installing one these days choose a wireless option.

There is only one reason to install wireless. Sloth.

I run a wired LAN and a Wireless one. I have LAN sockets in many of the
rooms, but wireless side has the major advantage that I can make use of
it anywhere I happen to be range, which is anywhere in the house and
most of the garden.

A decent wireless door bell has the same advantage, in that I can take
the receiver bell unit anywhere with me. I often spend time in the
garage/ workshop remote from the house and if I'm expecting an arrival,
I can take the bell along with me.

I long ago (before the days of wireless phones) wired up telephone
sockets around the entire house and included one in the garage. Only
one of those sockets is now used, for the wireless phone. If I'm
expecting a call, I carry the phone around with me.

Not a matter of sloth, a much more convenient system.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk