Need to add an outlet above or below an existing outlet? This video explains how to do just that without the need for mudding ...

Adding a single outlet can feel like a tiny upgrade, but the moment you touch that receptacle, a major breaker panel rule can kick in. Modern electrical codes treat any extension of a circuit as new ...

You probably CAN do it yourself, but if you're not familiar with the codes, I wouldn't. There are special codes that apply to bathroom outlets (need GFI, as you said), so either study up and do it ...