Will be tricky to find someone. I had my new house prewired for the light switch controller and relay driver. Total cost for prewiring - cat 6 to each light switch and electrical cable from the lights to the switch board was AUD2000, that didn’t include the cost of CAT6 as electrical company wanted to charge 5 times more than it cost.
I was wiring the switchboard with relays myself and then just asked a certified electrician to have a look and confirm if it was electrically sound before I turned the system on. He was very surprised about how clean was the job and that there were no issues when we turned it on. But he said that for the job like that they would charge a lot - 3-4-5k and it would be very hard to find someone who would agree to help.
But you might be lucky in finding someone who is interested not only for the money but just to have that experience in building home automation system.