He suffers from too many wet dreams; he wakes up and finds wetness but he does not remember having a dream

If a person
wakes up and finds some wetness, one of three scenarios must apply: 

1-

He is
certain that it is maniy, in which case he must do ghusl, whether he
remembers having an erotic dream or not. 

2-

He is
certain that it is not maniy, in which case he does not have to do ghusl,
but he should wash whatever it got onto, because it comes under the same
ruling as urine. 

3-

He does not
know whether it is maniy or not. This is subject to further discussion: 

(i)
If he remembers
having an erotic dream whilst he slept, he should regard it as maniy and do
ghusl, because of the hadeeth of Umm Salamah (may Allaah be pleased with
her) when she asked the Prophet (peace and blessings of Allaah be upon
him) about a woman who sees in her dream what a man sees – does she have to
do ghusl? He said: “Yes, if she sees water.” This indicates that it is
obligatory to do ghusl for one who has an erotic dream and sees water
(wetness).

(ii)
If he did not see
anything in his dream, if his sleep was preceded by thoughts of intercourse,
he should regard it as madhiy. If his sleep was not preceded by such
thoughts then there is a difference of scholarly opinion.

Some said that he should do ghusl so as to be
on the safe side.

And some said that he does not have to do
ghusl, which is the correct view, because the basic principle is that a
person is as he originally was.

End quote
from Fataawa al-Tahaarah by Shaykh Ibn ‘Uthaymeen (may Allaah have
mercy on him), p. 221. 

The fuqaha’
have stated that the smell of wet maniy is like the smell of dough or the
pollen of date palms, and the smell of dry maniy is like the smell of egg
whites. Mataalib Ooli al-Nuha (1/162). 

It makes no
difference whether that happens once or twice a week or more. Every time you
experience a wet dream you must do ghusl. You should not get worried because
this happens, because the reason for it may be that this is the nature of
the body, or some kinds of food, and so on. 

And Allaah knows best.