A signal is not clearance
Calibrate the tool on the actual wall according to its instructions. Scan slowly in one direction, mark the start and end of each signal, then repeat from the other direction. A broad, repeatable center can indicate framing; a narrow, irregular, deep, or isolated signal can have another cause.
Check outlets, switches, plumbing fixtures, radiators, and both sides of the wall. A framing pattern near a wiring or plumbing route still does not make the center safe to drill. Use the smallest possible fastener only after the construction is understood and the tool maker’s limitations are respected.
Limits
No tool or wall was tested. This article does not identify a hidden service, certify a drilling point, or replace electrical/plumbing detection and professional assessment.
Sources and related reading
See Also
If you want to move from general advice into actual product choices, start with When to Upgrade Window Weather Stripping: Signs, Timing, and Costs for U.S. Homes, Spigot Replacement: What U.S. Homeowners Should Check Before Buying and Installing, and What to Look for in a Basin Wrench for Tight Plumbing Jobs.
For a wider picture after the basics, Wood Filler vs. Putty: Which Should You Use for Wood Repairs? and Klein Tools ET310 Review: A No-Nonsense Circuit Breaker Finder are the next places to read.