Have you ever been in the ceiling of a house? Particularly one that been there a while.
Some still have the old rubber insulated cables.
As a former electrician, I can verify that the ceiling of a house is a very dangerous place. Not only because of the confined spaces and the heat, but because of cables, in various levels of deterioration, draped across bearers etc. Also, there are cable junction boxes which may not have been installed securely.
Anyone who goes into a ceiling should have been given a level of training to allow them to identify types of cable, signs of heat stress, and exactly how to install batts without risk to electrical cables.
And, there should also be a safety person, keeping an eye on what is happening.
