Are you sure about GFCIs and ungrounded outlets? Should the test button work?

	The NEC, section 210-7(d), and CEC, section 26-700(9), are quite
	explicit that GFCIs are a legal substitute for a grounded outlet
	in an existing installation where there is no ground available in
	the outlet box.

	But your local codes may vary.  As for the TEST button -- there's
	a resistor connecting the LOAD side of the hot wire to the LINE
	side of the neutral wire when you press the TEST button.  Current
	through this resistor shows up as an imbalance, and trips the GFCI.
	This is a simple, passive, and reliable test, and doesn't require
	a real ground to work.  If your GFCI does not trip when you press
	the TEST button, it is very probably defective or miswired.  Again:
	if the test button doesn't work, something's broken, and potentially
	dangerous.  The problem should be corrected immediately.

	The instructions that come with some GFCIs specify that the ground
	wire must be connected.  We do not know why they say this.  The
	causes may be as mundane as an old instruction sheet, or with the
	formalities of UL or CSA listing -- perhaps the device was never
	tested without the ground wire being connected.  On the other hand,
	UL or CSA approval should only have been granted if the device
	behaves properly in *all* listed applications, including ungrounded
	outlet replacement.  (One of us called Leviton; their GFCIs are
	labeled for installation on grounded circuits only.  The technician
	was surprised to see that; he agreed that the NEC does not require
	it, and promised to investigate.)