Advice on light switch replacement in old house
That's a standard plain light switch. Any home store, electrical supply house, or even Wal-Mart can set you up with the right thing.  

I realize that some people don't want to waste their Prime membership and so they buy everything on Amazon, but you should not buy electrical supplies on Amazon for 2 reasons:  


Most Amazon listings are actually Amazon Marketplace, an eBay-like flea market of not-necessarily-cheap Chinese junk. It's very difficult to tell the difference. Even if you watch out for "Ships from and sold by Amazon.com", you can get counterfeits.  Using cheap Chinese on mains electrical is not a good plan. 
Electrical gear is low value, quite heavy, and stocked everywhere.  A $50 roll of wire weighs 27 pounds.  That switch you need is 60 cents. As such, the business doesn't lend itself to mail-order; so there are few people selling. This has a very adverse effect on price.  Online generally, you have what I call the "I don't wanna ship it price", and on Prime you have the "third party sellers pay for Prime shipping" price. 


If you really like the Amazon model, use Home Depot. Use their "Pickup in store" option. They'll cheerfully pick the order for you and text you when it's ready.  At the store they have something like Amazon Locker where  you can pick up your order contactless.