Checking on our electrics, extension leads over here! (5)
I believe the answer is:
cooee
'over here' is the definition.
(informal UK way of getting someone's attention)
'checking on our electrics extension leads' is the wordplay.
'leads' indicates taking the first letters.
The first letters of 'checking on our electrics extension' is 'COOEE'.
(Other definitions for cooee that I've seen before include "Cry to attract attention" , "Call attracting attention" .)