I found a rectangular trapezoid 12V equipment light for about $14 and a toggle switch for $4. I had some terminals, bunt connectors, and some 12 gauge wire already in the shop.
When selecting a light, be sure to get a trapezoid type, as it will have a wider angle of light opposed to a more traditional headlight that my be more of a spotlight.
When I saw that somebody had asked about adding a headlight to a Snapper here in the Instructables forum, I felt inspired to share mine.
Step 1: Mount the Headlight
I used a punch to set the hole position then drilled with a high speed step bit.
I also drilled a small hole just above the bracket for the +12V wire to pass through. I grounded to a screw on the squeeze bottle cup holder.
Step 2: Mount the On/Off Toggle Switch
In the pictures, you can see the fuse body in the wire and the base of the switch. Just behind here is the battery. I wired directly to the positive terminal of the battery.
Step 3: Routing the +12V Wire Though the Frame
I used some semi rigid wire as a snake, taping to the +12V wire, and pushed it thru the frame like feeding conduit. I found it much easier to work from the front to the rear, believe me. It worked really well when I realized I needed to go from front to rear! There is a hole already there where the key switch wires were already run, so I used that.
I attached to the key switch first, pulled the excess back out the front, and spliced to the headlight red wire with a bunt connector.
Step 4: Finished!
I did some final adjusting in the dark to get the angle just right.
In the future, I may add some smaller lights to the sides and / or rear....