This is an enclosure for a C14-sized IEC connector module with a switch & fuse. This enclosure was designed for this specific model from Amazon: https://www.amazon.com/gp/product/B082ZFRV1B
The STL file will need to be rotated in order to print. The part shown in the photo was printed in ABS on a Bambu Lab X1C. An additional test part was printed in PLA on a P1P - neither print required support.
The mounting holes for the IEC module have enlarged bosses behind them in order to make it easy to install M3 heat set inserts.
The author marked this model as their own original creation.