Alright
@JLiz, against my better judgement I'll toss out the following... Just remember curiosity killed the cat.
Download the following program on any computer that is on the network in the office - Advanced IP Scanner
Advanced IP Scanner 2.4.3021
What the above program does is scans the network to show you all the connected network devices on said network. It will show you all the computers, printers, wireless/wired devices that have an IP. Some may not be obvious what they are others will directly say HP Printer. But, it will provide you the IP address to ever device and if you want you can simply start typing those IP's listed into your web browser to see if you end up at a camera or NVR login page.
Smart Phone Apps - If you have an android device download the free program called "Wifi Annalyzer" and continue your snooping. This will show you all the networks (wireless) and the devices around you as well as tell you what network they are connected to. If you have iOS you can download something called "Network Analyzer lite" and get most of the same info. Both these are Free
downloads.
Proceed with caution though with any/all the above - my personal feeling is still "mind your own business" since it is work related - however, I am a curious individual as well and would do all the above with little care in the world, so I'll just toss out a few ideas, do with them as you will.