Mickey Fickey is the TV friendly version of Mother
Fucker.
It first appeared when TBS first aired Spike Lee's Do The Right Thing back in the 90's, overdubbing all uses of the word "mother
fucker" with "mickey fickey". This actually made some of the scenes, especially the part where the guy is trying to buy 20 D batteries, quite funny.
"D! MICKEY FICKEY, D!"
The term has since grown in popularity as people use it in place of mother
fucker to be funny.