Resident switching from can to cup (8)
I believe the answer is:
occupant
'resident' is the definition.
(I know that occupant is a type of resident)
'from can to cup' is the wordplay.
'from' indicates an anagram (the anagram comes from the same letters).
'can'+'to'+'cup'='cantocup'
'cantocup' with letters rearranged gives 'OCCUPANT'.
'switching' is the link.
This may not be right. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for occupant that I've seen before include "One holding position or residing in house" , "Person residing in a property" , "Indweller" , "Holder of a position or office" , "Inhabitant, resident" .)