SIMPLE TOUCH ALARM CIRCUIT:-
          
                                                             Touch switch is only a conducting metal sheet that acts as touch sensor. The 555 touch switch is not a touch capacitive sensor; it is only a metal touch sensor button. Using this you can turn on and off devices by single touch.

Components used:-

1. IC 555
2. LED
3. Touch pad (Any conducting sheet)
4. Connecting wires
5. Battery

CIRCUIT DIAGRAM:-
                          

by watching this video we can make touch switch.