I have a home built in 1950 and a laundry room added sometime in the unknown future. There is a light switch that seems to be emitting electricity according to my Fluke voltage tester. I noticed it while replacing the switch. When I move the tester anywhere within an inch of the box, even without touching anything, it detects voltage. The two gang box is metal and the wiring looks like it's been there at least a decade. It does not appear to be grounded.
I have never been shocked by the light switch but am concerned. Why is it doing this? Is it unsafe? How do you fix it?