aid / aide
Help versus a helper.
Aid is a noun meaning help (financial aid) and a verb meaning to help (to aid the search). Aide is a noun only, a person who assists: a legislative aide, a nurse’s aide. Do not write aide for the help itself, or aid for the staff member.
Examples
Use The package included medical aid.
Use The governor’s press aide fielded calls all night.
Avoid The governor’s press aid fielded calls all night. (Change aid to aide.)