[supapolice]

If they've requested the wrong Item be returned, It's done so for a reason- replacement or refund.

I've yet to personally experience an Investigation opened for the wrong Item received method.

Do you think if I bought an EVGA RTX 2060 and sent back an EVGA 1050ti or an EVGA 1060 they would fall for it? I can't really think of anything of similar weight besides the previous graphics c(spam)ards. (all single fans)

It's not possible to conclusively say whether they'll check the Item on return. Depending on their workload and other factors, sometimes they don't bother.

Just send back a stock Item that weighs roughly the same.

I want to start off with an x470 motherboard (2.29 pounds) , so I thought about buying d cell batteries, but motherboard boxes are usually long right? And batteries are usually packed in boxes so I am clueless. Do you have any personal experience swapping a mobo?