It sure could be. It could also be one of a dozen other connections in the system. I would check any fuses you can find, and if they look fine, pop the switch out and check for continuity with a test light or multi-meter. If the switch checks out OK, pull the wires off the pto clutch and check for current there. I wouldn't throw any parts at it until I poked around with a test light. It could be anything from a connector that fell off to a defective pto clutch. Won't know until you do some digging.