Have a feeling that may be common (5)
I believe the answer is:
sense
I believe this clue is a double definition.
'have a feeling' is the first definition.
(I've seen this in another clue)
'may be common' is the second definition.
(I've seen this before)
'that' acts as a link.
(Other definitions for sense that I've seen before include "Could be common or horse" , "eg Vision, hearing" , "Meaning; perception" , "Meaning of a word or expression" , "One of five main faculties" .)