Haha... Jokes

Here are some jokes I created, let me know how (un)funny/corny you think they are.

Joke 1.
Why are mailmen so extreme?......
Because they are always pushing the envelope.

Joke 2.
Why are Catholic roof cleaners so steadfast?....
Because they are always on a mission.

Joke 3 (Requires knowledge of physics).
A cop pulls over an electron and asks "Do you know how fast you were going?" and the electron responds "No, but I know exactly where I was".