the motor runs to keep the inside cold.

Its hot on the outside because the motor is connected to a compressor that pumps all the cooling fluid into the coils at the back, when stuff gets compressed it gets hot, the compressed coolant then goes through a very small hole where it becomes a mist. this mist is what runs through pipes inside the fridge. the mist tries to take in heat so it can form a gas (much like if you spray an aerosol can onto your hand, as the aerosol contents evaportate away your hand gets colder.) The mist (turned into a gas by now) is compressed back into the hot coils at the back.

The refrigeration regeneration system on the outside of the refrigerator builds heat, which is dissipated into the environment. The internal system is comprised of coils / tubes where chilled gases are circulated, There is insulation in the housing shell, and there are seals on the doors, to keep the hot out and the cold in.

already been done:

Refrigeration works by moving heat from a place where you don’t want it, to a place where it is less objectionable. So the heat is being taken from inside the refrigerator and moved to the outside the refrigerator along with the heat of the motor and compressor. That is accomplished by the changing state of the refrigerant. A liquid must absorb heat to turn into a gas. That happens inside the unit. That gas must then give up heat to turn into a liquid. That happens outside the unit. For instance, a one ton block of ice will take 12000 BTU’s of heat to turn into water. That water will then have to give up 12000 BTU’s of heat to turn back into ice. Refrigerant does the same thing with the help of differing the pressures.