Why do Jews kiss walls?

Jews do not randomly walk around kissing walls, but there is 1 wall in Israel that Jews travel to just so they can pray there. that wall is known as the Western Wall. it is the only part of the outer wall of the Jews' Holy Temple that is still in existence today, so it is a very holy wall and the presence of God is stronger there than anywhere else. it is a great merit to pray at that wall, and Jews believe that you can write a prayer on a piece of paper and stick it in between the bricks of the wall, and God will answer you. this is not only for Jews. Non Jews can come and pray at the wall too, and if God chooses to, He will answer them. See 1 Kings ch.8.

Many Jews also customarily kiss their finger before or after touching a mezuzah. The mezuzah is a container with a Torah-parchment affixed to Jewish doors (Deuteronomy ch. 6).