Does a dry spot found on one's underwear, without remembering a wet dream, necessitate ghusl?

It is obligatory to perform ghusl (ritual bath) for anyone who has had a wet dream and sees traces of semen on their clothes, even if it is dry. If one sees traces of semen on their clothes but does not recall a wet dream, ghusl is obligatory, and the prayers from the last time they slept in those clothes must be repeated. This is if one is certain that what they saw is semen. However, if one doubts whether it is semen or something else, some scholars hold that one has a choice between the two doubtful possibilities. Others believe that it should be given the ruling of both. Still others believe that ghusl is not obligatory because the obligation is doubtful. The most preferable is to perform ghusl due to its congruence with the transmitted reports and to remove doubt. Some inclined towards preferring the view of the Shafi’is, which states that if one doubts whether what came out is semen or something else, they have a choice between the two.