Warner saying "Go to jail"? (6)
I believe the answer is:
beacon
'go to jail?' is the definition.
(be a convict)
I can't explain the remainder of the clue.
(Other definitions for beacon that I've seen before include "Warning light in the distance" , "Signal fire - signalling buoy" , "Hilltop signal fire" , "Warning or guiding device" , "Guiding device - signal fire" .)