Twig it’s some sort of electrical device (6)
I believe the answer is:
switch
'twig' is the definition.
(thesaurus)
'it's some sort of electrical device' is the wordplay.
I cannot really understand how this works, but
'it's' could be 'it' (I've seen this in other clues) and 'it' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for switch that I've seen before include "Device for opening and closing electric circuits" , "Change over - whip" , "birch" , "One may be off" , "Exchange positions for flexible rod or whip" .)