Power via Cat 5 cable - Hardwiring Solution for Doorbells

Hello, My home is 20 years old. Front door was wired only with Cat 5 cable to a Fon box that ring the doorbell via our wired phones. Wired phones are a thinkg of the past. My Fon device only delivered 4 volts. I bought a doorbell transformer (adjustable 10-24 volts) and used the Cat 5 (4 wires for each) and am able to deliver 18 volts without problem. I'm sure someone else has thought of this but I thought I would share it. I used the solid color wires on one and the stripped wires on the other. Immediately upon turning on the transformer the app went from battery 95% to Hardwired. Tim Brooks