This is the bracket that connects the ground spike to a Hampton Bay NXT-SL-12 / Nextech SKU# 1005554635 Solar Light.
Mine broke and I remade the part in OnShape so that I didn't have to throw out a working solar light because of broken plastic.
It's not perfect but it does the job. Hopefully others can use this to save some money and prevent e-waste over broken plastic.
Remember to print in PETG / ABS / ASA / PA for UV resistance - PLA degrades and becomes brittle in sunlight. You'll need to use supports inside the hole, and inside the nut capture. I set mine to support at 25 degree overhangs.
The author marked this model as their own original creation.