I need to replace a dual single pole light switch (two switches stacked) in a single box. My issue is the old switch has terminals for all the existing wires (3 neutral and 2 hot wires), but the new switch only has 4 terminals (2 hot, 2 neutral). The old switch has completely separate switches, the top a standard switch and the bottom switch labled "A.C. only". The "A.C. only" switch has 1 hot terminal and 2 neutral terminals, while the standard switch has the traditional one hot and neutral terminals. This standard switch operates the room ceiling fan and light-I don't know what the "A.C. only" switch is for and haven't been able to track these wires down. They do not operate the outlets in the room. Additionally, both black wires are independently hot. So when I wire the new switches, the top switch will contain the celing fan and light hot and neutral. Can I combine the 2 remaining neutrals together with a feeder wire so they will fit the open neutral post on the bottom switch? Is it safe and code correct to do so, even though I don't know where these wires go and what they are for? Also, since the black wires are independently hot, should I assume they operate on separate circuits and therefore remove the break-off tab? The house was built in 1935 with full lathe and plaster, so I'm not inclined to get into the walls to find out where these unknown wires run.