Oh bongo, I hope you didn't steal it.
And btw there's no such thing as ac/dc current. It's one or the other. DC comes from batteries, solar panels, simple generators. It's short for DIRECT current.
AC has to come from an inverter. It's alternating current. I believe it's for ease of transfer over the trunk lines...
Putting a new cord on something and doing wall wiring are a bit different.
And when you do a replacement cord, you have to make sure it can carry the current. Otherwise the resistance is too high, and it can overheat and start a fire. So if you've got say a 1000 HID, you need a nice heavy-duty replacement cord rated for like 18A at 120v (if you're on 120 and the lamps is designed for that).
No stealing street lights!!! You can buy them at the hardware store and keep your morals intact!