Why would the switched leads read 2.5 volts while key is off

I just installed a illuminated switch for a reverse light. Red when key is on ,Green when light is on. Thats when I saw while key is off the Red led was still dimly lit.
While key is off,
My orange switched wires are reading 2.5 volts on the meter. And of course anything connected to them (hand,thumb warmer,and of course the just installed a illuminated light for a reverse light.
I unplugged everything down to the orange leads and broke out the volt meter

What would be the cause?
When I first got it I had a problem with battery dieing ,Took it to dealer,they said some mumbo jumbo about just needing a charge.
Now I’m thinking ….
if I left the hand warmer switch "on"while the key is off that would cause the battery to drop.
Any suggestions?

Why would the switched leads read 2.5 volts while key is off

I just installed a illuminated switch for a reverse light. Red when key is on ,Green when light is on. Thats when I saw while key is off the Red led was still dimly lit.
While key is off,
My orange switched wires are reading 2.5 volts on the meter. And of course anything connected to them (hand,thumb warmer,and of course the just installed a illuminated light for a reverse light.
I unplugged everything down to the orange leads and broke out the volt meter

What would be the cause?
When I first got it I had a problem with battery dieing ,Took it to dealer,they said some mumbo jumbo about just needing a charge.
Now I’m thinking ….
if I left the hand warmer switch "on"while the key is off that would cause the battery to drop.
Any suggestions?