Someone on Ebay got scammed for $29.89 but at least the shipping was free!
A dime is supposed to weigh 2.27 grams.
A single clad layer should weigh, 0.40619g +/- 0.05g
both sides missing could be light weight by up to 0.81228g =/- 0.10g.
If it's missing one or both clad layers it should be underweight and weigh around 1.8g or so, and in the case of both sides missing 1.46g or so and it should be visibly thin.
Now, if the Sheet itself were missing the clad layers and nobody caught it, it would still weigh around 2.27g, because it would be rolled out to the correct spec thickness. this is something super rare though, even more rare would be the copper core running out and only getting 2 clad layers pressed together, which in theory also shouldn't be underweight due to rolling the metal strip to achieve specified thickness. unless it was at the very end of the strip I suppose.
in any case, the pictured coin, and the ebay sale isn't any of the above. but this would be the process in identifying when it actually is one. The weight and thickness should make sense for what you see.