What I bought is a cheap yard light you stick in the ground. So I just stuck it in a foot of water. Problem solved. You can take the extension off the light, and so the light might fit in a wide mouth canning jar. With a weight in the jar to keep it upright, you would have a floating light.
Well I bought one yesterday and put it in last night. I used a plastic wide mouth jar and it work. The light and jar came to about $9.00.
The one issue was that I saw very few bugs near the light and didn't see fish eating a the few bus I saw.
I may move it to an area of the pond that is darker since my yard light shines on parts of the pond.
