Re: WOOHOO!!! + grounding rod OR plug? Re: Earthing, Grounding, Barefooting...waWaWOWZAH (must read methinks)

Please check your sheet with the tester in the following way:
Plug your sheet in as normal. Place one hand on the sheet while holding the tester in the other hand and with one finger on the silver button on back of tester. A green light would show that the body is grounded when touching the sheet.
The reason for perhaps the light not going on: you aren't pressing hard enough on the tester. The surface fabric of the poly\cotton sheet sometimes prevents the button from contacting the conductive silver fibers of the sheet. The surface seems smooth, but if you were to look at it with a microscope you would see "hills and valleys."
The skin on the hands or feet is soft and makes good contact with the conductive fibers as the pliant surface of the skin, unlike the hard metal button, will bend around poly/cotton fibers and make good contact with the conductive fibers. Give that a shot.
Also try drinking more water. Some people are poor conductors simply because they are dehydrated.