I have a 120 V 25amp fused disconnect switch, which is protected by a 30 amp MCB. The fused switch disconnect is no longer servicing anything. Can I run 1/2" Emt from the Fused disconnect to a weatherproof 15amp Gfci which is fed with 14 gauge wire. Should I use 12 awg cable, I would also reduce the MCB and the fuses in the switch disconnect. I would prefer to run a new circuit instead of adding on to a fused disconect switch. Is there anything in the NEC code book which states that you can either do this or not. personally i think its a bad idea, I am a 1st year apprentice and I seem to learn more via teaching myself due to poor teaching via the journeymen that I work under. I hope that this is not a silly question to ask I am reading the Nec 2014 but it can be slightly overwhelming.