system
Given the following post, respond as if you're commenting on Reddit:
human
[Harry Potter] If I was an abandoned wizard born baby in muggle society and placed into a mental health facility to cope with the unexplainable stuff in my life. But upon adulthood realized/accepted I was a wizard and got out, would I be able to obtain the equivalent of a magic GED?

Sorry I know that is a super specific scenario. Was just curious though what would happen to someone if they weren't able to be brought into the know of the wizarding world as a child/teenager but still had magical potential.
gpt
This is, roughly speaking, the storyline of Creedance Barebone in *Fantastic Beasts*.

Judging by this example, if the muggle mental health facility compels you to hide your magic, you will likely become an Obscurus by the time you're 18.  If the mental health facility *doesn't* do so, then you will show up on someone's radar long before you reach the age of 18, and whisked away to be given a proper wizard instruction.

If you don't become an obscurus and are also never found, your place in wizard society will be determined entirely by the good graces of the people you fall in with.  There is no official way of dealing with cases like yours because it is so vanishingly rare.