Being female I have never sat in the super secret chairs near the chapel pulpit. Is each chapel unique or is there a holy of holy button panel on the priesthood chairs.

Would it be easy to reach over and turn it back on?

In the chapel where I grew up, there were 3 seats on the left front of the stand (facing the congregation) for the bishopric. Just to the right of those seats was a console that contained controls that could raise or lower the lectern as needed, and also contained the volume control for the microphone. It also had a button to turn on a small light on the lectern to tell the speaker that their time was up. So a member of the bishopric could cut the mic from his seat. I imagine other chapels have a similar setup.

The one I grew up in had this but it didn't have a warning light. Said building was constructed in the fifties so it must be a newer innovation.

It's really not meant to be a secret. I don't even think cutting mics is factored in during chapel construction; the person who controls the mic during church can turn the microphone on and off.

Do they still have mics to pass around or do you have to go up front?

It would be easy to sneak in a few days before fast and testimony meeting, and solder a wire accross the electrical contacts in bishop's disconnect button. It would be fun to watch as he pushes the button with futility a few days later when you start saying things that he does not approve of. Someone would need to drag you off of the stand in view of everyone, not a pretty scene, especially if you're a twelve year old girl.