I think that I was just being given a sealed letter, supposedly with a letter and some money, but I don't think that I will do this.   I didn't react appropriately at the time;  I should have said, " Let me think about it.".  Instead, I gleefully smiled and said, "Sure, why not?".

Sometimes, my good intentions go before my common sense. 

It might be totally innocent.............and then again, maybe not.