Boomers excellent posting on hosting an open house included my response concerning security.
The topic is worthy of a second posting – especially when both security and safety are the topic.
Your experience with security needs at an open house?
Example: One need for guests to enter the house is usually a request to use the restroom. To limit entrance into our home, we rely on open house guests asking us to use the restroom. We then have them use a nearby entrance and then inside have one or two direction arrows to the main bath. In this manner both my wife and I have some idea who has entered and when they return. I have been told having a “restroom” sign outside does encourage the curious to enter and look around.
Safety needs?
For our open houses, I take out a one million dollar policy with our home insurer - either for the one or two days. I remember it was cheap.