Well in 35 years of R/C Modeling I'v never seen this.

Back story.

I bought some new switches from an online vendor, I'm not going to name names because many Companies are selling the same Chinese made switch under different labels it's the style in the picture below I'm sure many of you use.

Anyway, I installed 2 in my New Extra 300, one for the Rx, one for the ignition battery, with brand new Nimh batteries

First day out with the plane after charging over night, no problem, Madiened the plane without any issues
Second day out I had charged the plane but it sat a day or two before I headed to the field, normally this isn't a problem, but I get to the field and the Rx battery is dead???
I figured I left the Rx on. So I charged it with my Hyperion EOS0606i charger and fly a couple times,, no apparent battery issues.

Today a week later I go to work on the plane and the battery is dead dead again?? WTH?

So after doing some checking with my volt meter I come to find the switch is bleeding voltage when in the off position. With a full charged 5 cell pack the volt meter reads .295 volts when off. With full charged 4 cell pack .190 volts when off. I couldn't believe my eyes so I checked with a couple other of the same style switchs, those have no issues.

I only post this as a warning to others, check your equipment with a voltmeter, the quality of products isn't what it once was

good luck