Some more strange superstitions here.

Although I regard myself as not being superstitious, I must confess to having some difficulty in shaking off the habits taught to me as a child; not putting new shoes on a table, placing a coin in a purse before making a gift of it, so I suppose I am helping to perpetuate these silly superstitions.
With issues like walking under ladders, an element of common sense is evident and likewise, the habit of refusing the third light from a lit match has it's roots in the trenches of WW1. If a German sniper was alerted by the flare of a struck match, by the time the lit match was offered to the second smoker the sniper would have taken aim, and on the third light, he would pull the trigger.
These days the danger wouldn't come from snipers but more likely from the anti-smoking crusaders. That's why I still wouldn't take the third light!