Go off booklet at regular intervals (4)
I believe the answer is:
bolt
'go off' is the definition.
('bolt' can be a synonym of 'go off')
'booklet at regular intervals' is the wordplay.
'at regular intervals' means one should take alternating letters.
The alternate letters of 'booklet' are 'BOLT'.
(Other definitions for bolt that I've seen before include "From the blue, it's a great surprise" , "Rush away - fastening bar" , "Eat hurriedly" , "From the blue, it's a big surprise" , "Fastening pin; run away" .)