I'm running a switched dedicated circuit, through EMT conduit, outside to a GFCI receptacle for an exhaust blower. The conduit has to pass through both a cinder block and a brick wall so it's a pain to install. My intent is to mate the conduit with the back of a weatherproof outlet box that is installed on the face of the brick wall. It would be convenient to have access to an addtional non-switched receptacle at that same outside location (different circuit). Unfortunately, there really isn't any unobtrusive way for me to install a second outlet box nearby. Are there any code requirements that would prevent me from putting in a double-gang box, with an additional duplex GFCI receptacle on a different circuit, run through the same conduit? If that's ok, then am I right in assuming that in the box, I should interconnect all of the grounds, but not interconnect the neutral (white) wires from the two circuits?

i have a hallway with 3 switches that control one light. i am planning on updating the switches to a teeter-totter type. my question is what kind of switches do i need to buy? do i need three 4-way switches or one 4-way and two 3-way. any help would be greatly appreciated. thanks!