WASHINGTON - HOUSEHOLDS across the land are infested with vampires. That's what energy experts call those gizmos with two sharp teeth that dig into a wall socket and suck juice all night long. All day long, too, and all year long.

Most people assume that when they turn off the television set it stops drawing power.

But that's not how most TV's (and VCR's and other electronic devices) work. They remain ever in standby mode, silently sipping energy to the tune of 1,000 kilowatt hours a year per household, awaiting the signal to roar into action.

"As a country we pay $1 billion a year to power our TV's and VCR's while they're turned off," said Maria T. Vargas, a spokeswoman for the Environmental Protection Agency's Energy Star program, which sets voluntary standards for energy use, and grants its ratings to the most efficient products.

There are billions of vampires in the United States, drawing more than enough current in the typical house to light a 100-watt light bulb 24/7, according to Lawrence Berkeley National Laboratories, a research arm of the Energy Department.