On Tue, 10 Dec 2013 05:45:31 -0800 (PST), "
wrote:

If the box has no neutral, then there is no code compliant
way to make the switch that requires it work. The issue is
that a programmable switch needs to be powered somehow. That
could be by a battery, through the hot and neutral, or by
using the load circuit. The latter is why the other switch
has a minimum load of 25W. Without some kind of minimal load
for a small current to flow through and power the switch even
when it's off, it would have no power. That small current flows
through the bulb when off and it's enough for thw switch, but
so tiny it won't light the bulb at all.

The minimum it said it needed was actually 40W.

Does the switch really draw 40W for its own use? That seems like a lot
for a small electronic circuit. It does have an LED screen that could be
on Hi all the time depending on user settings. I have mine set to dim
after 8 seconds.

With a regular toggle switch, off is an open circuit (no current
flowing), right?