What is wrong with my sentence 我的同屋睡觉时候想开屋门一点点?
Since  睡觉 (to sleep) is a verb that doesn't take object, 

时候 (time) as a noun cannot follow 睡觉 directly. To resolve the conflict, we  have to add 的 after 睡觉 to make it an adjectival phrase '睡觉的' as in "睡觉的时候" (sleeping time) -- That would then be grammatically correct

In English, the object is usually placed before  the adverbial phrase -- as in   "open the door a little bit" 

But in Chinese, the object is usually placed after the adverbial phrase -- as in "开一点点屋门" ( the object '屋门' follows the adverbial phrase '一点点' )