New motion-sensitive light switches installed at a university are keeping professors on their toes.

Traditional toggle switches were replaced by the energy-saving devices in 180 offices at California State University at Northridge.Professors say it was a dimwitted idea.

"There was a woman across the hall engaging in all sorts of gymnastics in her office to keep the light on," said Professor Max Lupal, who had the device removed because it observed only a wall and didn't pick up movement.

His colleague James Sefton complained he had to get up from his chair 10 times in three hours and wave to convince the switch he was there.

University engineer Alan McDonald said the $110 switches were part of a $1.1 million energy-saving project. The entire cost of the Watt Watcher switches was $20,000.