Some types of "silent" light switches, may contain liquid mercury in a metal or glass enclosure.
It is illegal to place mercury-containing products in the trash.
If mercury is spilled in your home, do not vacuum it up. Immediately call the Minnesota Pollution Control Agency at 651.649.5451 for proper cleanup procedures, or visit the U.S. Environmental Protection Agency (EPA)
Keep the mercury switch intact and bring it to a household hazardous waste collection site for free.