The most common and most likely answer to this crossword clue is the 7 letter word CRESSET
I've seen this crossword clue in The Guardian
C
R
E
S
S
E
T
More clues leading to the result CRESSET
Buddy explains!

The straight part
We know that "One may shed some light" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case one may shed some light = cresset.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 CRESSET mean?
CRESSET noun- A metal cup, suspended from a pole and filled with burning pitch etc; once used as portable illumination.
- (coopering) A small furnace or iron cage to hold fire for charring the inside of a cask, and making the staves flexible.