Determining if two words share a letter

Any hints about how I'd tackle this in Twine Harlowe?

E.g. I'd want a positive result if the words were "eyes" and "smile" (both contain e and s), or a negative result if the words were "eyes" and "blink" (no letters in common).

Something to do with splitting a string into an array of substrings for starters, I guess

Thank you!