Somewhere in this world, someone might be facing the same problem as (1) me (2) mine (3) I am.
Let’s try the first :
(1) Somewhere in this world, someone might be facing the same problem as me.
That means someone might be facing the same problem as me facing it : this is a ‘’heavy’’ sentence, it sounds incorrect.
(2) Somewhere in this world, someone might be facing the same problem as mine.
That means someone might be facing the same problem as ‘’ my problem’’; so the point is made on the problem itself that someone could face. It’s correct.
(3) Somewhere in this world, someone might be facing the same problem as I am.
That means someone might be facing the same problem as I am ‘’facing this problem’’ ; the focus is on the ACTION that I am doing, I compare the action that I am doing with the same action someone will do .
it’s correct .
Here is some other rules, to decide whether to use the subject or object pronoun after the words than or as, mentally complete the sentence.
Examples: 1- Mia_lia is as smart as she/her.
If we mentally complete the sentence, we would say, " Mia_lia is as smart as she is." Therefore, she is the correct answer.
2- Jura is taller than I/me.
Mentally completing the sentence, we have, "Jura is taller than I am."
3- Eliot would rather talk to her than I/me.
We can mentally complete this sentence in two ways: "Eliot would rather talk to her than to me." OR "Eliot would rather talk to her than I would." As you can see, the meaning will change depending on the pronoun you choose.
Hope I helped