The most common and most likely answer to this crossword clue is the 4 plus 3 letter word FILM SET
I've seen this crossword clue in The Guardian
F
I
L
M
S
E
T
Buddy explains!
The straight part
We know that "This might be Elm Street, if in production" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case this might be elm street, if in production = film set.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does FILM SET mean?
FILM SET noun- The enclosure in which a film scene is shot; includes scenery and props