Apaches
In 1977, I lived in a semi-rural area, and some local parents got together to arrange a screening of a public safety film called "Apaches".

The basic premise was that farms are dangerous (which they are), and you should watch out. Fair enough.

But the way in which the group of kids in the film were relentlessly massacred by farm machinery, slurry pits, poisonous chemicals and falling gates left a very different impression on my mind. If you step on a farm, it seemed to say, there's a very good chance you won't be leaving alive!

Having sat through this Anglian Farmyard Massacre, I avoided farms like the plague for many years, and even now view slurry pits with some trepidation. For anyone who'd like to be similarly traumatized, here's a YouTube link.
( Amish Information Systems hates misplaced, commas, Mon 28 May 2012, 10:43, 2 replies)

I remember being shown a video called "Safe as Houses"
which was all clips of kids electrocuting, burning or otherwise maiming themselves by messing around with household items. It was quite graphic and it really horrified me at the age of 8 or thereabouts. Still, it didn't make me scared of household items, just made me a bit apprehensive any time the teacher "We're all going to the TV room now children" and wonder what we were going to be subjected to.
( Photoshop Bitch 2014 edition, Mon 28 May 2012, 10:50, closed)

When searching...
...it helps if you spell "Apaches" correctly. This has already been brought up on page 1 by gp_guineapig.

My horror remains undimmed by time, however.
( Amish Information Systems hates misplaced, commas, Mon 28 May 2012, 11:33, closed)