Watermill WASP 66 twin impeller shower pump

Dear Team, My pump is about 7 years old and is normally used for 2 to 3 showers a day. Recently I had to change the black impeller as the force had been lost at the hot end. I have noticed flashing blue sparks coming out of the vent at the under surface of the pump at the black impeller end. The flashes last for several seconds at a time, are intermittent but regular. The shower pump works fine otherwise after changing the impeller. I am not sure if the flashes also occurred before but I never specifically looked for it. I am told that it could be a sign of worn out carbon brushes. Could you please advise on the following please. 1. What would or could happen if I continue to use the pump in its present condition? Is it dangerous to use the pump and in particular is there a risk of fire or other electrical hazard? 2. Do I need to buy a new pump or this is due to worn out brushes which must and can be changed? Do you sell brushes and is it easy to change them? 3. Do you also sell the plastic fan for the above pump and if so how much does it cost? I would be most grateful for any help or advice you could offer, please. Regards. R.K.Sinha