A tiny project box (18mm x 30mm x 11mm) with lid that fits a USB 12v step down voltage regulator. Solder +/- wires and glue down the lid. I used this to hide mini dashcam wires in my auto's map light.
Fits this part perfectly: https://www.amazon.com/dp/B087ZRGMPS?psc=1&ref=ppx_yo2_dt_b_product_details
The author hasn't provided the model origin yet.