What would we do without the
ball point pen spring and vaseline 
Last night the pair of them brought back to life a ceiling light switch in my mothers bungalow at 20:05. The original spring had broken a couple of coils off and when I tried to stretch it it snapped as it had gone brittle. So out came the ball point pens to donate a spring. Found one and lubed the mechanism with vaseline and hey presto, all is working fine
. She has a new switch which will be installed sooner rather than later.
Don't think the springs are big enough for RC cars though
Post about how you've used of vaseline only if you don't want it deleting
Did have a video but due to lack of skills on those pesky mobile phone thingys I forgot to save it
What other uses have you put the little spring to?