´It was narrated from 'Aishah that:` The Prophet said: "If anyone of wakes up and sees some wetness, but he does not think that he had an erotic dream, let him have a bath. But if he thinks that he had an erotic dream but he does not see any wetness, then he does not have to take a bath."
Hadith Referenceسنن ابن ماجه / أبواب التيمم / 612
Hadith Gradingالألبانی:حسن | زبیر علی زئی:ضعيف, إسناده ضعيف, سنن أبي داود (236) ترمذي (113), انوار الصحيفه، صفحه نمبر 400