According to Larry R. Wright :

Do I need to move the electrical outlet box to account for the thickness of
tiles or is it safe just to use longer screws for the outlet and face
plate?

There are adapters you can buy that add up to about an inch worth
of depth to a box. Cheap too. Ask for a "box extender".
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.