The switch is definitely a possibility, but other problems can also cause this.
Bad switch, needs replaced.
Broken wiring in power nozzle, wands, hose, or canister.
Bad PN motor.
I strongly recommend taking it to the nearest authorized Aerus Electrolux store for a diagnosis (should be free). Allowing them to do any repairs necessary is recommended, as well. This will ensure it's done correctly.
http://www.aerushome.com/storelocator/
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