ORIGINAL: Missileman
Most of these switches are simple 3 pole switches with a common, a normally closed contact and a normally open contact.
The common hooks up to your battery (usually the connector on the side that has 2 sets of wires) the normally closed contact is used for charging and has a complete circuit when the switch is in the off position. The normally open contact goes to your receiver. When you turn your switch on your normally open contact closes and your normally closed contact opens (that is why it is impossible to charge with the switch on.)
The charge lead should only go to the battery, if it is feeding your receiver then either you have a bad switch or the wrong lead hooked up to your receiver. (it can easily fool you because the switch will seem to work but you will actually be moving the switch to what should be the off position thinking it is the on position,)
Well, if you want to get technical they're single pole double throw switches (SPDT).
That's why it's bothering me that it can both charge and be on at the same time. Perhaps a leaf in the switch is bent, I don't know. I would replace it.