Firm proposal to employ Mike brings excitement (9)
I believe the answer is:
commotion
'excitement' is the definition.
(thesaurus)
'firm proposal to employ mike' is the wordplay.
'firm' becomes 'co' (a firm is a company).
'proposal' becomes 'motion' (proposal at a meeting).
'to employ' means one lot of letters goes inside another.
'mike' becomes 'M' (phonetic alphabet: alpha, bravo, charlie etc.).
'motion' placed around 'm' is 'mmotion'.
'co'+'mmotion'='COMMOTION'
'brings' acts as a link.
(Other definitions for commotion that I've seen before include "Rumpus" , "Disorderly outburst" , "Row" .)