[JackCh]

In theory yes¹, but in practice I would expect it to be a tricky time-consuming process. How would you differentiate between a legitimate electronic device on the other of the wall, and an illegitimate electronic device embedded inside the wall? The difference between those may only be a few inches.

I don't think this is one of those problems looking for a technical solution. What's needed is a legal/social solution: an aggressive campaign for publicly identifying and shaming perpetrators, with very harsh punishments handed out.

¹ From what I know traditional "bug detectors" work by trying to induce the bug to broadcast and then detecting that broadcast signal. But "metal detector" style bug detectors that instead simply look for circuits seem like they should be possible.