'Excellency' in the Bible

"From: Claudius Lysias To: Governor Felix Greetings, Your Excellency:

"Your Excellency Felix, since we are enjoying lasting peace because of you, and since reforms for this nation are being brought about through your foresight, we always and everywhere acknowledge it with profound gratitude.

But Paul said, "I'm not out of my mind, Your Excellency Festus. I'm reporting what is absolutely true.