Light wont turn off - Panasonic KX-T7630 Corded Phone

Of course it will. Which one are you trying to turn off? Probably the ried one on top. Press MESSAGE and look at the display. It will tell you why it's lit, and one of the buttons will be CLEAR.
When you clear them all, the light goes out. Since the 7630 has no backlit display, it can't be that one. If it's an extension that is not equipped, you'll press PROGRAM the lit button, and CLEAR or (IIRC) TRANSFER and STORE.

How's that work for you?

Carl