No, you can'd cap the wires and leave them in the wall. The wires don't have to be removed from the wall, but you have to make sure that they are not powered under any circumstances if they are left there.

bostonhome-
Those wires are undoubtedly running to several locations and rewiring will be a fair amount of work. Just how do you intend to control the lights these switches were running to if you remove this box?

You could wirenut the leads as if they had not been cut into for the switch (black to black, red to red)and then put a blank coverplate over the switchbox. You don't have to have a switch there, but the box must remain accessible if it contains a splice.

At this point, I'd just live with it.