I have several encounters with the white lady. For those who do not understand cultures from Singapore, Malaysia and Indonesia, let me explain.
In non-Muslim society, many refer as a white lady. But for those who understand religions from these 3 countries, it is referred to as 'Pontianak/Langsuir/Kuntilanak'. They feed on babies, especially boys. The Muslims believed that a woman might turn into one of those mentioned above if they died from child labor if glass beads are not inserted in the dead woman's mouth immediately.
I'm not sure which one of these attacked me but 'she' was wearing a white robe. It happened during my pregnancy periods. We were renting at Pasir Ris and most of the time I am home alone. Almost every Wednesday, 'she' appeared in my room, in a dark corner. I was scared because the fetus inside me is a boy. I couldn't move nor talk. I was angry that I can't have total control of myself; I recited verses from the Koran. But I did not get to complete the verse. I got really mad and gathering last ounce of whatever's in me and cursed her (she was laughing and swiftly moved here and there and gradually near me). She disappeared. I was not dreaming and I know that. When she disappeared, I turned on the lights and called up my husband - he never believes in such things. It happened a lot of times even when my husband was around. I'm in tune to their presence I guess.
I'd like to clarify though that this isn't a Muslim belief. This is a cultural belief and in this situation it's a Malay belief. But I think outside the Malay community, other societies might have their own version of the 'cik pon'.
But since the poster is Muslim, she tried to fight it with Quranic verses. In Islam, so-called evil spirits such as this are all, what we call, bad 'jinns'. Yup, all. No matter what you call it, it's actually of the same specie, 'jinn'. These things want nothing but to steer you away from God. The reason why it laughed was probably because it wanted to distract the poster so that she would stop praying (i.e. Say God's name) and give up.
That's the basic explanation of these things with regards to beliefs in culture and religion because they're not the same. I'm no expert but this is my understanding.
Take care all:)