Supernatural...(in my room)

something scary thing happen to me .. yeah and it true... i don't know wat is actually happen... ok here wat happened..

this past few days i keep goin to library study for preparing my final exam. so every morning about 10am i will leave my room and head to library..den after that something scary happened or weird happened whenever i came back from library....

4 days go lib since sunday... 4 things happen... everytime i came bac frm library, when i open my room door, the sitting fans in my room will block the door or at least the door will bang on the fans.. i dunno how this happened. as wat i rmbr, when i wan go out to lib, my fans was never close to the door and no matter how , the door when open will never bang the fans.. so today it happened again, once i came back, it bang, i try ask my housemates for some xplaination, may b they sneak to my room when i not at home, but they din sneak in, and feel weird when i tell them....

arghhh... some more, they tell me might be got " xiao ren" ( a small ghost) in my room =.=..
cham...i dun have any idea how to xplain this strange phenomenon.. is it might be due to wind? since i not close my window? but imposibble rite, the height n weight of fan wont be blown away by the wind ...

Can anyone have some scientific explaination to tell what goins on? it only happen when i goin to lib in the morning.. at night , it doesn't happened.. kinda scaryyyyyyy ...arghh..T__T

helpp me....