TOPIC: Question on electrical in garage

Sean, there you go advertising for Lowes again. I personaly prefer Home Depot. 

I have a problem any time I see a receptacle, like a 20amp GFI, on an incompatible circuit.  It indicates unprofessional, or sloppy, work.  That is no guarantee that the wiring will be correct.

If a multi-wire 20amp receptacle, like a GFI with a red traveler and both hot wires get their power from the same leg of the transformer, is installed on a 15amp circuit, and wired incorrectly, the load on the neutral line might be additive.  Too much and for too long overheating can be a problem. 

Any time I see incompatibility I mention it on the report.  Then it never comes back to bite me.