The most common and most likely answer to this crossword clue is the 3 plus 7 plus 4 plus 8 letter word THE WONTIES (THE WILLIES)
I've seen this crossword clue in The Guardian
T
H
E
W
O
N
T
I
E
S
(
T
H
E
W
I
L
L
I
E
S
)
Buddy explains!
The straight part
We know that "a fright" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case a fright = the wonties (the willies).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.