I remember reading this English (could be a translation) short story ~20 years ago in my school. There was an executioner who executed convicts on an electric chair. He never cared about (or looked into) the convicts. Then he comes across the fact the next convict is a young man of a cheerful nature. (I don't remember if that exact word is used). And while going through the things of this young man, he comes across this watch which he gifted to his son, and it was too late.
I don't remember much details about that story, except the use of the phrase "throwing the switch". I looked online but couldn't find it.
What short story is this?