This swivel adapter works with this Heated Shower Mirror on Amazon: https://www.amazon.com/gp/product/B0CN16WPBZ/
You can print the two parts and put them together and install them as shown in the pictures. I'd recommend putting an M3x40mm screw (or a similar diameter/length screw) in the provided screw hole. This will add tension so the mirror stays in whatever position you put it in.
This is the recommended print orientation:

The author marked this model as their own original creation.