It really is so short it would be less hassle to provide instructions on how to make it. So, in Tasker...
New Profile -> give it a name -> State -> Net -> Wifi Connected -> hit magnifying glass on SSID -> Select your home SSID -> Back -> New Task -> give it a name "Mobile Data off" -> Add -> Net -> Mobile Data -> Set Off -> Back -> Back (should be back on Profiles list now). Long press "Mobile Data off" -> Add Exit Task -> New Task -> give it a name "Mobile Data on" -> Add -> Net -> Mobile Data -> Set On -> Back several times to home screen.
Done.