Hello,
I know this has been suggested before, but a fan in the fridge is not such
a bad idea.  I just installed mine.  Here is how to get an inexpensive
fridge fan.
I obtained a small GE pistol dryer (if you go to yard sales, you will find
these or other driers for about $1.00) and removed the fan-motor.  According
to Steve Johnson, these fan motors work (usually) on dc current.  Mine does.
I then wired this in series with my previously-described cabinet fan ....
that's the one from Kmart that pulls heat out from behind the fridge ...
so that if one runs, they both run.  I ran 2 wires out through the top of the
fridge and under the stove top on to my cabinet fan connection.
Oh, to attach the thing to the top of the fridge, I used a piece of velcro.
Stuart Hutton