I'm wiring a bathroom. I've got a fan, 2 lights and an outlet. I need to connect all of the white legs together (i.e. five #12 wires)--I think that's too many for a wire nut. Is there something like a screw block something like you would find in a breaker box that you could feed the five wires into yet small enough to fit in the back of a light or switch box?

Hold on a minute, please.

1) NEC requires a 20 Amp, 120 volt GFCI protected receptacle for bathrooms.

2) If there is only one bathroom, then the NEC allows the entire bathroom to be serviced by that 20 amp line.

3) If you choose to use the one circuit for both the receptacle and everything else, you must set the GFCI receptacle at the end of the circuit. If it is at the start of the circuit and is protecting the entire circuit, then if the GFCI trips, you are now standing alone in the dark.

3) Personally, I would run two circuits to a bathroom. One 15 amp circuit for lights and fan. And one 20 amp receptacle. Hair dryers are amp hogs. If you have one circuit and you are running the fan, to clear the haze, the light to see what you are doing and a hair dryer, Trip, there goes the breaker and there your wife or child stands in the dark, with wet hair screaming for you because, "You did this to them!"

You can use a gray Ideal wire nut or 3 M scotchlok to splice 5 - #12 .