Fire, for example, in electrical component? (7)
I believe the answer is:
element
This clue is a double definition.
'fire for example' is the first definition.
(fire is one of the four classical elements)
'electrical component?' is the second definition.
(part of an oven or other device which heats up)
'in' acts as a link.
(Other definitions for element that I've seen before include "Ideal situation for someone" , "Singular ingredient" , "Basic constituent; aspect" , "Constituent of universe" , "part of cooker" .)