1. light bulb or LED or CFL. Converts electrical energy to heat and light. 2. Smoke detector has a radiation source to ionize any smoke particles and then charged plates to attract them, which causes an electrical current, which sets off the alarm. .
Well / A security company will either sell you the components to install a system yourself or install them for you with prices ranging from free if you sign up for monthly monitoring (paying the first and last month fees on a two- to four-year contract) to $100 -$1,500 or more, depending on the number and type of sensors and the features chosen. Monitoring fees range from $8 -$40 or more monthly, or $95 -$480 each year.
