stand-in
nounUK /ˈstænd ɪn/
US /ˈstænd ɪn/
A stand-in is a person who takes someone else's place for a while.
The actor's stand-in waited on set while the lights were fixed.
OTHER MEANINGS
2. A person who does another person's job temporarily.
She was a stand-in for the manager during the holiday.
3. Something used in place of another thing.
This box is just a stand-in for a real table.
4. A person who replaces an actor during filming for lighting or camera checks.
The stand-in stood where the star would later act.