The electrical switch function is to interrupt an electrical flow in an electrical circuit (on/off function). Mercury switches have been commonly used in bimetal thermostats (coffee machines, etc.).
Mercury switches are mainly found in large household appliances (EU-WEEE category 1) and only to a very limited extent in ITC appliances (EU-WEEE category 3). Because of the presence of the poisonous mercury, these switches have been eliminated from most application. They are still used in vending machines with "tilt alarms".
Mercury is encapsulated in a sealed glass capsule, which might be protected by a case. It has the aspect of a big drop of silvery moving liquid.
Caution during dismantling
Never break the sealed envelope!!!
Caution during storage
Store separately to avoid shock with hard and heavy objects. Keep it in a sealed recipient, and keep it in a cool place away from any heat sources (e.g. direct sunlight).
The switches have to be sent to a proper recycler without breaking them.
Source of Information
Dismantling Guide for IT Equipment, which was elaborated within the SRI project and financially supported by SECO and UNIDO, June 2015