Light switch/panel in 1/2 Bath

[druganjk@gmail.com]

I have a 2018 Miramar 35.3 and the light switch in the 1/2 bath does not work. I know this switch is removable and should still work when you remove it from the wall. Does anyone know if this unit has a replaceable battery or do I need to order a new control panel/switch. If I do have to replace it does anyone know where I can purchase it. Pictures attached.
Thanks

[Rocky-in-AR]

The battery is on the back in your first picture. It’s silver and about the size of a nickel. You just slide it out. Pay attention when you take it out which side is up. You should be able to get one at Walmart.

[wrapped]

Yup what Rocky said

[m1noel]

Also, you can check the battery condition of your remote switches from the main panel.