Picked up these branded 4ft long, chainable hanging lights. (Mine are specifically these Dakason lights ← amazon link, non-affiliate.)
Normally you can only “link” them in a straight line, but I wanted a nice square, so I modeled up the end caps and rails, then made a transition piece that slides into the ends and leaves an internal channel for the linkage wire to route.
I printed these in PETG on a X1C and it's a VERY tight fit, but they hold extremely well. (Strong enough that I had no issues lifting the square by hand without any stress signs.) If the tolerances are too tight, I've included the Fusion360 file so you can tinker with it yourself.
I've also included a “wire wind”. I believe the intent once you've hung the lights is that you trim the wire to length. However, cutting it will leave frayed steel cable (ugh) and then you could never adjust them back down. So I made these small wire winds that allow you to clean up the excess hanging steel line and tuck it away nicely. (Compare the pictures where the wire is just bundled up vs. where there are little pucks above.)
The author marked this model as their own original creation.