ok and then 12V power supply for rf board and piezo buzzers on it right ?

 

How about a wireless doorbell?

 

How about a wireless doorbell?

I've got two kinds, from different Chinese companies. Both use 12 V "N" batteries in the transmitters. Range is not great. They might work over 20 m in free air, but not through walls.

ak

 

ok and then 12V power supply for rf board and piezo buzzers on it right ?

Yes 12V for board. From there you have a relay out so you can drive whatever you want. The board can be powered using any simple 12 VDC wall wart.

Ron