Typically I fit in 7-8 kegs in a chest freezer aka Amul ice-cream refrigerator. Just attach a thermostat and you are good to go. You can buy your keezer attachments here.
If you are unsure how many kegs you can fit in, cut out 8.5 inches circular discs (you can also use serving plates of 8.5-9 inches diameter). Place it inside the refrigerator to cover the area.
If you are trying to fit your corny homebrew keg in a fermentation chamber or mini-fridge, just make sure that you have knee-length height in your keg which is 25 inches for 19L and 14.25 inches for 9.5 Liters version (plus an additional inch or two for maneuvering)