Muffin fans are a slang name for computer fans aren't they?
Hypothetically speaking [as you should get a qualified electrician to do any electrical work in your home yada yada yada] they are dead easy to use.
Just buy a 12v adaptor [one that has adjustable voltage switch is good to make the fan slower or faster] strip the end of the wires off, strip the end of the wires off of the fan, match and join the wires, tape over them or whatever
turn on the power and bingo you got fannage
