Man is laying out source of electricity (5)
I believe the answer is:
mains
'source of electricity' is the definition.
'mains' can be an answer for 'source' (I have seen 'source of power' mean 'mains' so perhaps 'source' could also mean 'mains'). I am unsure of the 'of electricity' bit.
'man is laying out' is the wordplay.
'laying out' indicates an anagram.
'man'+'is'='manis'
'manis' anagrammed gives 'MAINS'.
Can you help me to learn more?
(Other definitions for mains that I've seen before include "Utility network" , "Source of electricity or gas" , "Water, gas or electricity supply" , "source of power" , "seen in cockpit" .)