Stud finder

Hello, I'm trying to build a stud finder sensor for my Arduino but I have had little luck finding a "stud finder" sensor. Do they have another name they go buy?

I have not seen that discussed.
I just have one from Home Depot. Finds wood studs, metal studs, electrical wiring.

I need just the sensor, so it can send feedback to the Arduino. Buying one from home depot would be a waste of money has I would just rip out all of the internals to get to the sensor.

I don't know what sensor is used, sorry.

A decent stud finder can be had for under $15. It is hard to imagine finding just a ‘sensor’ for much less. And it’s likely not so much a function of the sensor (which is probably a common hall effect device, capacitance sensor or inductive pickup or combination of those) but rather the circuitry that goes along with them that provides sensitivity and accuracy.

If it was me, I would be planning a cheap stud finder with an added interface to my Arduino that translates the light or buzzer signal of the finder into a digital signal.

As it seems like you can't buy just the sensor I will have to go with hacking one from Home Depot.