The other night, while attempting to attach a bracket for an above-the-range microwave, I noticed my son having difficulty using/reading my 20-year old stud finder. So I went looking, on-line, for a replacement.
Holy Goblins, Batman! The first place I looked, Harbor Freight, had one for $9.99 (#92375). But, golly, it not only finds wood and metal studs, it locates power conduits! For added convenience, the device has an integrated LED flashlight and, I'm not making this up, a built-in 36" tape measure!
HF has another model, for $16.95, but I was afraid to check its vitals. The more expensive model may very well check for running water and have a built-in drain snake and 7-function multimeter!
Point is, your old standby tool may have evolved into a more handy helper.