Found these on-line. I have not used anything like this but seems like a low cost solution you could explore.
https://www.harfington.com/products/
20pcs Waterproof Case Switch Covers Caps...
Type: Posts; User: DavL
Found these on-line. I have not used anything like this but seems like a low cost solution you could explore.
https://www.harfington.com/products/
20pcs Waterproof Case Switch Covers Caps...