here is a site that some what explains the fog remote hack
ScareFX: Modified a Gemmy Remote
but you can use a 120vac relay in place of the one he is using. however i recommend going with a low voltage coil relay and connecting the wall wart to you ac controller.
the remote will most likely be switching 120v ac so you will need a relay that has contacts rated for 120v and around 10 amps
WARNING VOLTAGES IN FOG MACHINES CAN BE VERY DANGEROUS never work on one while it's plugged in all ways be careful when dealing with electronics to not have the circuit uncovered while active.