Switch positions occasionally (2,3,3)
I believe this clue is a double definition.
'switch positions' is the first definition.
(a switch might be on or off)
'occasionally' is the second definition.
(I've seen this before)
(Other definitions for on and off that I've seen before include "Perhaps switch positions" , "Switch choices" , "Intermittently" , "Occasionally" , "periodically" .)
(Other definitions for off and on that I've seen before include "sometimes" , "Now and then, stop and start" , "Occasionally" , "the two sides at the Oval are this" , "Switch options" .)