When we built our haunted house 3 years ago, we installed all new electrical drops and a full monitored fire alarm system. The fire alarm system consisted of about 10 pull stations, 70 heat detectors, and 30 horn/strobes. Also included was an emergency annunciation system that activated and directed everyone out of the event. All the new electrical drops and emergency lighting that were installed were ran thru a panel of contactors. These contactors were held on by power that ran thru the fire alarm panel. If the fire alarm was activated, or we had a loss of power, the contactors all opened which shut down all the haunt lighting, audio, and animatronics, and forced all the emergency lighting and exit signs in to power off mode, which lit the place up bright white. IF it was an emergency situation and not a power loss, then the over head lights for the building were also automatically switched on.
The contactor system was designed and installed by me, but all the new electrical runs were installed by a proper contractor, and the fire alarm system was designed and installed by the monitoring company.