and then just search 3D printed cases. If you have the print file (usually .stl file) you can send it to a company online (there are many look them up) and they'll ship the print to your house.

915 is the radio frequency of the unlicensed band in the US, but look up what it is in your country, remember this won't penetrate walls so don't keep it inside expecting to reach anything and also remember to establish that people network because you can just as well flash a light with Morse code to transmit a message lol.