... Not sure I follow you. D'you mean so that you don't have the switch and do all your pickup selection via volume control of each pickup?
Technically yes, although it would only be able to give you two options you wouldn't already have, which would be the bridge and neck pickups without the middle, and all three pickups at once. There are, however, switching systems capable of giving you these combinations already (I think Fender's S-1 Switch can do this), and you have to remember how much of a pain it would be to do all your pickup selection by adjusting volume levels on the fly rather than just flicking a switch.
