I've removed our previous 20 year old garage door opener and am installing a new one. I'm now at the step of wiring the new control panel to the wall. The garage is finished, and the old control had wiring behind the drywall. There is a brown cable and inside it is a black and white wire, one end going to the control panel on the wall, and the other end coming out of the middle of the ceiling in the garage (to go to the old garage door opener).
I'm using a contactless voltage detector and it's detecting voltage on both of those black and white wires, even though there is no garage door opener (let alone one that is plugged in), and the voltage is detected at both ends of both of these wires. Why would this be? The control panel on the wall is just above a light switch, is it perhaps detecting some "phantom" voltage from that or something? I dont think that would explain why it is detected at the ceiling, where there is no light switch (there is a light, but a few feet away).
My new garage door opener came with a new control panel cable, so I can use that. But I wanted to reuse this wire if possible so that I dont need to put unsightly wires stapled to the drywall. However, I dont want to damage the new garage door opener with improper wiring.