Update:
In addition to the experimental small version for 20 cm printer beds, I also added a bigger version for 2 0.5 litre bottles (NRW size) due to demand

This is a working Refrigerator with peltier cooling. It has a storage capacity for two 0.5l cans and work like this:
A Peltier element an an ceramic plate with several semiconductors inside. When power this element with an voltage (in my case you can use 5V~15V) one side of the ceramic plate gets hot and the other sife gets cool. On both sides are heatsinks.
The air in the storage room is sucked in by a 40mm fan and led through the cooling fins of the heat sink. The cold air is then blown back into the storage room through an air duct at the top and bottom. The heat sink on the hot Peltier side is cooled by a 120mm fan. As a power supply I use a 12V switching power supply with 72W power. The fans are operated directly with the 12V. For the Peltier element, I also use a step-down converter that transforms the 12V down to a lower voltage. (I use 10V for the peltier)
There are already complete sets with Peltier Element heatsinks and fans to buy on Ebay. I used such a set with the Peltier Element TEC1-12706.
for example here:
https://www.ebay.de/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=DIY+Peltier&_sacat=0

In addition you need:

• two plastic hinges are required (The holes must be drilled depending on the hinge)
• 4 magnets (12mm x 3mm)
• a few M4 screws and nuts.
• a Step Down converter. I used one with a maximum output current of 5A.

There is a small hole on the bottom so that liquid, which can result from condensation on the cool heat sink, can drain off.

See drawing for wiring.

Note on the printing settings: Print the front part aligned on the back side and use the setting: Support structures only from the printing bed.

I added an experimental version for printer with 20cm Bed sizes. There i reduced the wall thickness (from 4mm to 2.5mm) and the height of the air duct. This will decrease the stability of the print but maybe 2.5mm is still enough. Also you need 5mm x 1mm magnets instead the 12mm x 3mm magnets for the door

Thanks to Lyl3 for the "Customizable Drawer Handle or Cabinet Handle" (https://www.thingiverse.com/thing:3911914) which i used for the door handle.
and unknownhand for the Monster Logo. (https://www.thingiverse.com/thing:44542)