I absolutely HATE the power/mode selector button on my Zircon studfinder! The lightest touch will turn the darn thing on and run the battery down. (It doesn't help that the battery used is a 9v either.) I can't tell you how many times I've gone into my toolbox, unzipped the handy Zircon carrying case, and found the thing "deader than a door nail."
Now I'm at the point of unplugging the battery after every use. This is not a convenience either.
Zircon if you're reading this; Use a simple slide switch to turn the unit off!!!!!!
I'm glad I got that off my chest.
Thank you, Mark