A bit crazy, and it could be a can of worms! (4)
I believe the answer is:
bait
'it could be a can of worms' is the definition.
The definition suggests a singular noun which matches the answer.
'a bit crazy' is the wordplay.
'crazy' indicates an anagram.
'a'+'bit'='abit'
'abit' anagrammed gives 'BAIT'.
'and' acts as a link.
Can you help me to learn more?
(Other definitions for bait that I've seen before include "Fishing lure" , "Enticement, lure" , "Set a trap with food" , "Angler's lure for fish" , "Lure; deliberately taunt" .)