The diagram below provides a visual reference for wiring of the components. This diagram was created using the software package Fritzing.
Use Adafruit's Fritzing parts library to create circuit diagrams for your projects. Download the library or just grab individual parts. Get the library and parts from GitHub - Adafruit Fritzing Parts.
Make the following connections between the Feather NRF52840 and the MCP9808
Make the following connections between the Feather NRF52840 and a SPDT slide-switch
Note that the Feather GND pad is shared between the MCP9808 and the switch.