1. Can a person afflicted with obsessive-compulsive disorder (OCD) build upon the greater number when in doubt about the number of prostrations, given that her doubt does not occur daily, and she fears that she may not be among those whose doubt is considered frequent? 2. Is ablution valid if a person afflicted with OCD sees a dream or events during light sleep in which she feels she was not completely unconscious?

You must turn away from and repel these whispers until Allah cures you. If Satan tries to delude you into thinking you are not afflicted by whispers, repel him and pay no mind.

As for light sleep, it does not nullify ablution according to some scholars. Its criterion is that one's full awareness is not lost, such as when a sleeping person hears a loud sound near them or feels something if it falls from their hand. However, if awareness is lost, then it is deep sleep, which nullifies ablution.

Dreams are considered by many scholars as a sign of sleep that nullifies ablution. So, if you are certain that you have invalidated your ablution, or if you had a dream, your ablution is nullified thereby. But if you are in doubt, the original state is that ablution is not nullified, because purity is established with certainty and is not removed by doubt. If you slept a light sleep and felt that you had invalidated your ablution, perform ablution if you are certain that it occurred. However, if you are in doubt, you are not required to perform ablution.