I made this to hold the remote to my tabcat (aka loc8tor) devices. It's just a little rectangular box. You may need to rotate this model to print it, make sure the open part is facing up.
Print perimeters of width 0.75mm or some divisor of that to get nice walls with no gaps.
Stick to wall with velcro, double stick tape
I used Gorilla tape, but you could use any double sided tape, VHB or Velcro might work well.