Employing a disguise.
The celebrity went unnoticed by her fans because she was in disguise.
The homeless man was actually a police officer in disguise working to catch drivers texting.
(figuratively) Seeming to be something else than what it actually is.
That so-called news story is really advertising in disguise.
Avoid flatterers, for they are thieves in disguise. William Penn
Another belief of mine; that everyone else my age is an adult, whereas I am merely in disguise. Margaret Atwood
What seems to us as bitter trials are often blessings in disguise. Oscar Wilde
It is a blessing in disguise. Japanese Proverb
A calamity is often a blessing in disguise. American Proverb
The praise of fools is censure in disguise. Dutch Proverb