Sure it's not the switch? Run it fully backwards and forwards quite a few times, which can often improve things without resorting to some switch cleaner. Though a squirt of switch cleaner may help for a while (Servisol 10 or Caig De-oxit).

Those Squier switches aren't the best and they do often fail after a time. Even the wafer switches fail from time to time but I generally find them more reliable.