Surplus military equipment is often a fantastic addition to a civilian's life. The equipment is well-made and is built to last in tough conditions that far surpass anything a civilian might put it through. In many cases, you can use the military-grade gear without making any changes, but a few categories do require adjustment. Lighting is one of these. What you use and how you use it may require rewiring or a little legal research.
Watch out for State Color Requirements
If you're trying to use vehicle lights, especially warning lights that you might find on construction equipment, be sure you are not using the wrong colors. Each state sets the rules for who uses which color (e.g., one state may use red for an emergency vehicle only, while others may allow red for a few non-emergency uses off-road). Flashing lights could be restricted to emergency services only, or various light patterns could be OK for construction vehicles that are on a work site and not the street.
LEDs and Older Lights
The military has been making a push to use more LED lighting in order to save energy and money, as well as reduce waste and time spent changing bulbs. Just as with civilian fixtures, the socket in these military fixtures can take any sort of "traditional" bulb. But if you are looking at a fixture that does not have a traditional-style socket, be sure the light type it uses is the one you want to use, too. If you're trying to switch to LEDs as well, you don't want a fixture that takes only fluorescent bulbs with non-traditional bases.
Connections and Conversions
If you get military equipment like trailers or lights that have to be wired into an electrical system, be sure the connections and plugs are compatible. Military equipment often has different connections that may require some DIY electrical work if you want to use them with a civilian vehicle or system. Take pictures of the connection you want to match and show the pictures to the salespeople at the company selling the equipment. That way you avoid miscommunications that could land you the wrong piece of equipment, or a piece that is harder to rewire than others.
These aren't insurmountable issues by any means, but they are ones you want to be aware of when you look at surplus military lighting. When you know what to expect, you have an easier time finding the equipment that really will work for you. Contact a military lighting manufacturer for more information.