It's probably from a metal halide setup. The light socket would probably tell you more and it looks like a mogul-style base. I'm sure only specific lights are meant to work with it, but I'm no expert on these lighting systems.

Once you find out what it's supposed to be for, you can buy the appropriate ballast, or if you like the hood you can buy the hood right now and remove the socket with the intention of mounting a new one in there when you get it.

Light hoods seems to be very easy to modify because they're just sheetmetal. You can make the holes larger if need be and you can put self-tapping screws into them to secure a new fixture in there.

Sorry I couldn't be of more help...

Sam

The hood is universal; you can put either a MH or HPS bulb in it. Since the cord was cut buy a new cord set when you buy the ballast. The ballast is the only item that MUST match the bulb type (MH, HPS) and wattage. The hood and the cord set work with any type or wattage of bulb.

Gbrendemuhl is correct. That looks looks a MOGUL socket, which is made for 100w to 1000w HID bulbs. A MOGUL socket looks like a normal houselamp type socket, just larger.

If you see a small electrical device with 3 wires coming out of it located near the socket, then it was used for a High Pressure Sodium lamp. The small electrical device would be an ignitor, which HPS's usually require. Just remove the ignitor if you want to use it for a Metal Halide lamp.

Zink