I figured it out...I think. Instead of two black wires in the box, I have a white and a black. The red should go on the white and the black on the black (although it does really matter which goes on which...I think). As for the real "white neutral", there are another couple of wires bound together, but not otherwise connected to a switch. This must be the "neutral white" wires that need to be connected to the 6615-P white wire. Under "troubleshooting" "light does not go on. Lamp neutral connection is not wired". Do I have this right?
The 6615 requires a Hot, Neutral, Load, and Ground. The Hot wire (carrying 120V) should go to the black lead. The Neutral should go to the white lead, and the Load wire should connect to the red lead that is not taped off. The other red lead is for a 3-way switch configuration. Ground should go to the green. The bundled wires that you mention may be your neutral, in which case you may need to tap off the bunch with the white lead, but you should get an electrical tester to identify the wires in the box before making any further attempts.
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