On a whim I picked up a 20 cu in carlon old-work box and shoved a DPS3005 power supply module into it... to my suprise it fit!
The DPS unit has springy plastic retention tabs that hold it snugly in the box, and I saw that there was still space at the bottom to mount some output jacks. I was pleased with how well it fit and stayed in place.
I used an old "decora" wall plate from my electrical bin and enlarged the rectangular opening with a utility knife so it would accept the module. I drilled two 3/4" spaced holes on the bottom of the plate and mounted some spare banana jacks (3/4" spacing is common for a variety of banana accessories). To hold the plate onto the box I cut some strips of scrap pvc board and used some small screws.
The wall plate keeps the DPS unit in place pretty nicely and I dare say it also adds a touch of finish.
A 30 volt supply from an old printer powers the unit. It's pretty wimpy but I haven't needed more than a 1/2 amp yet. My module can handle 5A and I did find another larger printer power supply that I can swap in. The power cable runs into one of the knock-outs in the back of the box but if I change supplies I'll use a dc power jack.
I've used other small power supplies that weighed so little that they slid around when you operated them or put the slightest strain on the output cord. Screwing the box to the shelf above my bench took care of that.
I haven't drilled any ventilation holes in the box or added an ON/OFF switch or even proper input jacks but there's plenty of room to do so. There's also ample space to add a small fan with maybe a pwm speed control if I ever get so inclined, but for now I'm just going to use it as is.