This is the case for a mini volt meter and momentary contact button
switch. I have a lithium battery in a motorcycle and found lithium
batteries get low, they just do not start. I added this volt meter to
monitor the condition of the battery. It's mounted by zip ties to a tube
handle on the motorcycle. Pressing the button on the top of the case
displays the voltage of the battery.

Components:
Mini 2-wire Volt Meter (3.2 – 30 VDC) from Adafruit
https://www.adafruit.com/products/460

Tactile Switch Buttons (6mm tall) from Adafruit
https://www.adafruit.com/products/1490

Two small screws

Printer Settings:

PLA (Black), 0.1mm Layer Height (First Layer 0.2mm), 20% infill, no support material, 190 degrees (195 degrees first layer).

Construction:

Note, this is a small enclosure, so putting this together may take
several test fits before final assembly. Take your time, it will all fit!

Test fit and file openings and drill holes if needed. Test fit the screws. Cut the two unused contacts of the switch, straighten the two
contacts and give them an outward bend. Start with the case back
and put the two contacts into the two outside holes in the switch
mounting brace and press the switch into place. Route the wire to
the switch, cut the red wire and connect and solder the cut ends to
the two contacts of the switch. The wires exit the case through holes in the back of the case. Move the wire and switch contacts out of
the way and put the case together. Two screws hold the case
together. The screws go in through the bracket, then into the case. Two zip ties can be put through the slots in the bracket to secure the meter to a frame tube. The meters wires connect to the battery.

The 123D Design file is included so you can make modifications to
the case or bracket for your application.

Press and hold the button on the top of the case to read the battery
voltage.