Last year we installed an above ground pool and pump. I installed a GFI outlet outside by splicing through an outlet inside a bedroom. All is well and fine. Well, I bought my wife a above the stove microwave. When it runs, it blows the circuit, it's on the same one as the pool pump. I traced the microwave 12g wire and it goes right into the circuit box where it's spliced together with the pool pump wire into one circuit. My question is, can I pull the wire for the microwave and splice it to another circuit (lights)? If so, do I need to spice it to the wire or can I just install it into the circuit itself? I don't see any circuits with two wires in them and that's why I ask. Just trying to limit the cut wires. Thanks

I would run a separate line, or more wires(if in conduit) and have each on own circuit. Use the existing box, and maybe an extension ring(for more room)Only connections will be there, receptacle, or panel.