Umm? More info needed. Are you referring to changing out the MAF housing? I haven't ever had to change mine out, but I guess one way to look at it is, if you are going with a CAI that is a larger diameter than the stock MAF housing itself, then yes a switch would be needed, but if the diameter is the same, then I never messed with it. Not enough of a difference for me to spend another $300 on.
If thats not what you are asking, just ignore me and carry on. (415am post lol)