In the UCMJ, the Commander-In-Chief (President, or, at state level, Governor) may dismiss any subordinate with cause at any time (https://revisor.mo.gov/main/OneSection.aspx?section=40.010&bid=1070&hl=). In our service, the Commander-In-Chief is the county Sheriff. A dismissal with cause may be appealed to a court-martial proceeding, but the court-martial is only empowered to consider converting the dismissal-with-cause to an administrative discharge (at least as far as the Auxiliary service record of the volunteer is concerned; an Auxiliary court-martial has no power over the Sheriff's Office to amend or change its policies). In either case, the volunteer leaves the service and may only be restored by an act of the Sheriff. An administrative discharge (with or without stated cause) by the county Sheriff may not be appealed.
In the Sheriff's Auxiliary, dismissal with cause or administrative discharge may be considered by any court-martial, regardless of size or type and the volunteer may be indefinitely suspended until the decision is reached.