What does φῶς reference in Acts 26:23? Cf. Ephesians 5:9. BDAG Greek-English Lexicon (page 1073) states:
"To be filled [with] Christian truth means ἐν τῷ φωτὶ περιπατεῖν 1 J[ohn] 1:7a, εἶναι 2:9, μένειν vs. 10."
In certain contexts, the word "light" may be substituted with "truth" salva veritate. Although, we can make a conceptual distinction between "light" and "truth," that does not necessarily mean that writers can't properly use "light" as a trope for ἀλήθεια or other godly qualities in some contexts. Interestingly, in the Greek papyri of Egypt, a wife is said to be τό φῶς τῆς οἰκίας (Sylloge Inscriptionum Graecorum 888).