Reverse lights confusion

[chucklawler]

I'm installing a backup cam in my 2011 Aveo sedan. Tapping into the reverse light wire I've found something quite confounding. First, both reverse lights work as they are supposed to. Key off, all wires cold, as expected. Key on in park, both wires to the reverse bulb (left side) are hot. Shift to reverse, light comes on, the positive is still hot, negative goes cold. Never seen a circuit work like this. Is this really the way its supposed to work on this car?

[Eg.h2o]

Yup…a lot of vehicles run hot + wires and then use a switch or relay to complete ground.
“Switch to ground” circuits.

[chucklawler]

Thanks for your reply. I guess I have to find another way to trigger the reverse cam.