Actually omit a switch without thinking (13)

I believe the answer is:

automatically

'without thinking' is the definition.
(without needing to think)

'actually omit a switch' is the wordplay.
'switch' indicates anagramming the letters.
'actually'+'omit'+'a'='actuallyomita'
'actuallyomita' with letters rearranged gives 'AUTOMATICALLY'.

I've seen this clue in the Sydney Morning Herald.

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