This is a replacement stake for the Harbor Freight "Solar Brushed Nickel LED Path Light" (item #60755). I suspect that it will work for many other yard lights as well. Certainly you could modify the OpenSCAD file to make appropriate adjustments for your particular light.
Note that this part will require printing with support. See the instructions for more details.
Here is a link to the original yard light:
You can either take the part as is and print it from the STL or you can modify the OpenSCAD to resize / scale to your needs.
I rotated the stake so it prints lying down and rotated so that two of the "fins" on the side of the stake are against the platform.
Because of all the slops and angles, you will need to print this with support. On my Solidoodle2, using Slic3r, I turned the support down a bit (to about 35 degrees) so that it only printed along the edges of the stake rather than filling in the entire underside between the two 'fins'.