How to Find a Listening Device in the Office?

Have you thought about getting IT involved? If someone hooked up a device to the company network, they should be able to detect it. Just make sure you're clear about your concerns when you report it.

I'm curious, what made you suspect there’s a listening device? Were there any specific incidents that raised your alarm?

First off, I’d suggest reaching out to management or HR instead of trying to play detective yourself. They’ll likely have the proper resources to investigate this sort of thing professionally.

If you're suspicious, try talking about something specific and see if that colleague mentions it later. It could be a way to gauge if they're truly in the loop or not.