The clue can be split into two parts and is based on two different definitions of the word FUDGE.
Newspaper had a box.
Basically a (fudge)-box which can be just called a Fudge is as merriam webster dictionary defines it 'a newspaper space left blank for the insertion of last-minute items.' So this clue hints at FUDGE.
for the sweetmeat
The for is merely used to split the clues, FUDGE is a sweet meat (in its second definition). So this clue hints at FUDGE.
Since the word FUDGE, fits both clues FUDGE is the answer.
I think I wrote something like this down previously: the clues could be hinting at an answer of FUDGE in the first definition. This whole clue could be saying that since FUDGE (as in the fudge-box and so also a 'box for fudge sweets' as an alternate definition, which is what the newspaper had) is the container for Fudge (the sweetmeat), the answer is FUDGE.