Situation
In the first scene, the performer uses a microphone-stand with a boom-arm (no microphone is used), instead a wig is hanging on the mic-stand.
It is standing when audience enters - in the one corner of the stage, where audience doesn't have to pass.
There is also a glove attached to a robot-vacuum-cleaner which is driving around on stage.
When audience is seated the performer pick up the glove and takes off stage.
I do a puppetry-number with these two props, when scene has ended the two props get pulled to the corner, where no audience is near and they stay there for the rest of the show.
For the last scene 3 remote controlled cars are used, they are driving around on stage + the robot-vacuum-cleaner.
The are controlled by the main performer + a second stage-hand person (from the performance crew).
One of the remote-controls are also handed to an audience-member.
Risks
These driving objects are possible to trip over, if one or more audience needed to rush out all of a sudden.
Measures
None of these moments where the props that moves are used are in dark situations - the house-lights are on, so they are easy to spot.
All the props are also in high-definition colors, which further makes them easy to see.
In intro-scene with "glove" driving around. The performer is present in space to greet people and therefor make sure people notice this driving props.
For "end" scene. There are two performer on stage controlling these driving props, which can be stopped and moved at any point, if emergency occurs.
The remote given to an audience is taken back before the end, and all the props are gathered and stopped in an area of the stage, which is not close to any escape-route for audience.
They are all using rechargeable batteries - no wires to electricity needed.