When I sleep even when I take nap suddendly I start laughing or sometimes very strange sound and this is common this happen several times. And this is another thing I want to tell that this is second time happen with me before some days ,. When came from office I took a small nap and suddenly again start laughing and when brother or my parents asked what happened I said nothing then I woke up and sat on bed start again laughing then just turn to weaping loudly. After some time I got normal like nothing happened with me.