Mention what you have noticed about extraction or ventilation, with the room, affected material and timing. A fan or vent being present does not settle whether it works appropriately or explains the mould. Send a wider view and accessible detail, and include condensation, known water incidents, earlier products and repairs. You do not need to test equipment or dismantle fittings for the enquiry. Give observations and uncertainty so assessment can consider the actual property concern.
A separate home clean has ordinary household tasks. It is not ventilation assessment, installation or a substitute for suitable mould work.