adding a NSS

Has anyone ever added a neutral safety switch to a 1969 or older car with a manual trans that did not originally have one.

Just looking for ideas ..... don't really want to change the pedal set out for a later set but I'm sure someone might have a creative way to add a little more goof proof.

I am not So much worried about myself but against better judgement I might let someone else drive my car and its a 68 with no NSS.