My whole family has switched over from regular toothbrushes to Oral B Pro 1000 electric toothbrushes (https://amzn.to/2Et0r1o). They're great, but they need recharging every week and we have limited bathroom counter space (and only one outlet). Even if we had the space, the charger base and cable just aren't very tidy looking to keep out all the time.
So, I figured I'd make a shelf over the outlet near our sink for the charger base to live on. Lucky for me, Thingiverse already had two great designs to work with. The first was omair94's design of an outlet shelf for a Google Home (https://www.thingiverse.com/thing:2851101). The second was villekl's design for a wall-mounted Oral B charging stand (https://www.thingiverse.com/thing:227356). There are dozens of variations of both designs if you need to work out something similar for a different outlet size or charging base type.
I don't remember my infill settings, but I suspect it was around 20-30%.
Tinkercad is a fast way to remix files, but one downside is that it interprets the curves of imported files with a bit of faceting and stepped layers. Both of these original files were very curvy, unfortunately. To restore the smoothness, I sanded it down with a rough grit and used 2-in-1 sandable primer/filler to fill in the gaps. I repeated this a few times, then moved over to a regular glossy white spray paint. Finally, I hit it with a clear polyacrylic spray.
For fitting it on the outlet, I initially thought I would use it to completely replace my existing outlet cover. For better or worse, though, the forward-curved edges reveal too much of the electrical box behind it, and it's not pretty.
My solution was to attach this over the the existing cover. The trick is to get slightly longer screws for attaching the two covers together, since the original screws that come with your cover probably won't accommodate the extra thickness. From my local hardware store I bought 4 brass 6-32 machine screws with oval heads similar to the original screws. I brought my original screw with me and just found a something a little longer (not sure the length I decided on, but your situation may vary anyway).