Mock ruins of half-hearted comic stories (7)
I believe the answer is:
follies
'mock ruins' is the definition.
(a folly is a structure made to look like a ruin)
'half-hearted comic stories' is the wordplay.
'half' becomes 'fo' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'hearted' indicates the central letters.
'comic' becomes 'sellers' (Peter Sellers).
'stories' becomes 'lies' (to tell stories can mean to lie).
The middle of 'sellers' is 'l'.
'fo'+'l'+'lies'='FOLLIES'
'of' acts as a link.
(Other definitions for follies that I've seen before include "Ornamental buildings with no practical purpose" , "Silly acts or ornamental buildings" , "Idiocies" , "Rash actions" .)