A method for operating a wind turbine, and the wind turbine comprises a generator for generating electrical power from wind, the generator having a generator axis, a nacelle for supporting the generator, and a tower for supporting the nacelle, the tower having a tower axis, and the method comprises the steps sensing at least one tower vibration by means of a vibration sensor, sensing a mechanical generator vibration, caused by at least one electrical fault, by means of the same vibration sensor, and controlling the wind turbine in dependence on the sensed tower vibration and the sensed generator vibration.