Depending on your sponsorship situation, attaching pay stubs can be an important piece of evidence to prove that your income claims are correct.
Types of common situations where paystubs might be important to attach:
You claimed that the US citizen sponsor has income through employment that contributes to meeting the financial bar
You claimed to use the intending immigrants income for the purposes of meeting the financial bar
Please see the sample pay stub below. It is not important that your pay stub looks exactly like this but it is important to ensure that the following details are present in your pay stub:
Name of employer
Your name
Period for the pay stub
wages
Most paystubs have other information which is great if you have it but is not needed.