Re: Indesit W93 washer switch rotates of own free will
It sounds like a heater failure, this could have damaged other components, not safe to keep using if it flashed then fused. When the control knob starts to rotate the neon light will flash a set number of times, if you count these it will give a code we can try and interpret for you.
Would advise getting the machine looked at ASAP, please pull the plug if you intend to investigate further.
Have a look here