Some mousetraps evident in part of church (4)
I believe the answer is:
apse
'part of church' is the definition.
('apse' is part of 'church')
'some mousetraps evident in' is the wordplay.
'some' indicates the answer is hidden within the clue (some of the parts of the word are used).
'APSE' is hidden in the letters of 'mousetraps evident in'.
(Other definitions for apse that I've seen before include "Strange peas in the church recess" , "Church recess with domed or arched roof" , "Recess at eastern end of a church" , "part of cathedral" , "Peas (anag) - found in church" .)