I am referring to the concept of Tzadikim Nistarim (lamed-vovniks)—the 36 hidden saints in the world because of whose righteousness the world continues to exist—addressed in this passage:
As a mystical concept, the number 36 is even more intriguing. It is said that at all times there are 36 special people in the world, and that were it not for them, all of them, if even one of them was missing, the world would come to an end. The two Hebrew letters for 36 are the lamed, which is 30, and the vav, which is 6. Therefore, these 36 are referred to as the Lamed-Vav Tzadikim. This widely-held belief, this most unusual Jewish concept is based on a Talmudic statement to the effect that in every generation 36 righteous "greet the Shechinah," the Divine Presence (Tractate Sanhedrin 97b; Tractate Sukkah 45b). (Source: Zwerin, Rabbi Raymond A. (September 15, 2002 / 5763). "THE 36 - WHO ARE THEY?". Temple Sinai, Denver: americanet.com. Archived from the original on Jan 18, 2003. Qtd. in http://en.m.wikipedia.org/wiki/Tzadikim_Nistarim)
I am wondering whether there is anything in religious literature that suggests that these people must be Jews. Is it possible that some are goyim?