I have a 5-year-old and he is totally obsessed with fans since he was 2. I am sure they’ll be okay. It might be related to some sensory-issue. The only tip I can give you is to limit the time that he can be with fans. I significantly reduced his obsession by limiting his time. He gets to play with his fans when I do household chores. He gets to watch “Fan” videos when he earns the watching time with his good deeds. When we go out to relatives/ friends’ houses we talk before-hand that he is not allowed to go switch on their fans. And if he behaves well he would get to see some videos after coming home. These restrictions worked like a charm. He slowly started playing with other stuffs during his non-Fan hours. Hope this helps.