Thank you Nastor for your prompt response. From your explanation, I guess there is no way to avoid that blinking on the LEDs. However (as Douglas comments) if the extractor created an independent circuit to the central box, do you think the problem will continue to persist?
It will decrease, disappear I don't know. That type of anomaly affects the network, and if the lines share pipe, there may be some induction (due to the alteration caused by the magnetic field), I really don't know. You can try adding a capacitor to the LEDs (flash inhibitor), to see if it filters something. I'm an electrician, imagine that the sine wave electrical alteration is seen with oscilloscopes.