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." (Using translation from Ibn Mājah 612)
"إِذَا استيقظ أحدُكم من نومِه فرأى بَلَلًا، ولم يَر أنَّهُ احتلمَ اغتسلَ، وإذا رأى أنهُ قدْ احتلمَ ولمْ يَرَ بَللًا فلا غُسلَ عليه".
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."
عَنِ النَّبِيِّ ﷺ قَالَ إِذَا اسْتَيْقَظَ أَحَدُكُمْ مِنْ نَوْمِهِ فَرَأَى بَلَلاً وَلَمْ يَرَ أَنَّهُ احْتَلَمَ اغْتَسَلَ وَإِذَا رَأَى أَنَّهُ قَدِ احْتَلَمَ وَلَمْ يَرَ بَلَلاً فَلاَ غُسْلَ عَلَيْهِ