On Tuesday, 7 June 2016 20:22:02 UTC+1, Lee wrote:

Any ideas anyone?

I know you said no electronics but there is an Instructable for a
project using an Arduino and a cheap ultrasonic sensor:
http://www.instructables.com/id/Meas...asonic-sensor/

Talk about doing it the hard way. This is a beginner bulb & battery level electronics exercise.

Did you get that lightswitch wired in yet?


NT