[acmegeek]

Would the Walabot fit the bill for you? I bought one when it first came out and seemed pretty good. I haven't messed with it in a couple years though.

https://walabot.com/see-through-walls

This seems like a pretty good review:

https://www.bobvila.com/articles/walabot-stud-finder/

[jpm_sd]

I tried one and it's pretty disappointing. Plenty of room for improvement.