וזרח משעיר למו הופיע מהר פארן
We find Goyim converting to Judaism and Lehavdil Yidden converting ch”v to other religions.
R.Akiva Eiger said*, “When Hashem went to the other nations to accept his Torah and they refused, there were some individuals, who were willing to accept the Torah but were scared and remained quiet. From them came the Geirim.
Also when the Bnei Yisroel saidנעשה ונשמע, There were some individuals who didn’t want the Torah but were embarrassed to say so.