Source: Harold W. Attridge, "Historiography," Jewish Writings of the Second Temple Period, ed. Michael E. Stone (Philadelphia: Fortress, 1984) 167.
"Moses, after the burning bush encounter, returns to Egypt where he is imprisoned. He miraculously escapes when, during the night, the doors of the prison miraculously open. (It was the parallel between this account and the report of the escape of Peter in Acts 12:3-17 which caught the attention of Clement of Alexandria.)"
Attridge is referring to the Jewish historian Artapanus (second century B.C.E.), who is cited by Clement of Alexandria in the Stromata (second-third centuries C.E.).
I'm not sure what Attridge has in mind here. I checked Clement's Stromata 1:23, which is where Clement refers to the story of Moses' release from prison. Clement doesn't mention Acts 12, but he does compare Moses to Peter in the sense that both killed people with the words of their mouths (Acts 5). Here's what Clement says:
"And the mystics say that he slew the Egyptian by a word only; as, certainly, Peter in the Acts is related to have slain by speech those who appropriated part of the price of the field, and lied (Acts v. 1). And so Artapanus, in his work On the Jews, relates 'that Moses, being shut up in custody by Chenephres, king of the Egyptians, on account of the people demanding to be let go from Egypt, the prison being opened by night, by the interposition of God, went forth, and reaching the palace, stood before the king as he slept, and aroused him; and that the latter, struck with what had taken place, bade Moses tell him the name of the God who had sent him; and that he, bending forward, told him in his ear; and that the king on hearing it fell speechless, but being supported by Moses, revived again.'"
Maybe Clement is saying something like "Moses and Peter are alike in such-and-such a way, but here's another example of their similarity." I don't know. I'm a little disappointed, however, because I was wondering how Clement accounted for the similarity between the two stories. I can picture modern scholars asserting that Acts copied the story of Moses' release from prison and applied it to Peter, but Clement of Alexandria wouldn't do that, even though he often accuses the pagans of plagiarizing off the Hebrews. He may just think that two similar events happened in history.