Two wire tail light help?

[62stepside longbox]

Hey guys, about a year ago I picked up some reproduction 39 Ford LED Taillights that I was going to mount in the rear of the fender on my stepside. When I bought them I saw that they had two wires, I assumed that one wire was for the signals/brake lights, and the other was for Taillights and they grounded themselves through the mounting point. But just yesterday I finally got around to messing with them and I found out that the black wire is for ground and the white wire is for power. Having only one power source can I even use these lights on my truck? Correct me if I'm wrong but when I turn on the signals both the lights might flash since they are linked through the Taillight wire. Any help is appreciated, thanks.