I’m not sure if the US Kmart has the same products as the Australian one, but I just got a battery powered set of Christmas lights that use 0505 white LEDs (Tiny). For those like me who have trouble seeing these littles LEDs let alone soldering to them, this is a great product. I’m sure the US price is even lower than the AU$5 a set of 24. Even come with a controller that can be set for Off On and Flashing.
Definitely have these in US stores - I have a string that looks like that stashed away for future use. I actually think it came from a Dollar Store, not KMart.
If you don’t like the bright white (i.e. blueish) colour you can make them a warmer white by applying some Tamiya Clear Yellow paint. It isn’t a perfect solution because the blue tone gives the painted lights a very slight greenish colour, but if you are modelling older incandescent lights it is better than the original bright white.