I see shops around here that require adding a service or making a change to an existing service, in which case you need to be a customer of the provider. But there are also a lot of shops that require just a purchase (phone, smart watch, etc., but not an accessory) with no activation, then a return. You don't need to be a customer of the provider, and you're not allowed to activate the item unless you intend to keep it. You're reimbursed any restocking fee. This sounds like the type of job you want, and the pay is the same as the other type.
I haven't done one yet, but plan on trying to get one as soon as my schedule frees up.
I learn something new every day, but not everyday!
I've learned to never trust spell-check or my phone's auto-fill feature.