Looking at Psalm 55:14, this verse refers to Jerusalem (i.e., God’s house). In the city, calamity and suffering reign. You ought to be safe in the city; the walls are there for your protection. But iniquity has a strong presence—both on the walls as well as in the city. Market squares are of great importance to a city, but if there is iniquity and trouble there, it will be a plague for the whole city. The heart of the city is sick.
The image of predators, hunting throughout the city, comes to mind here. See, for example, Isaiah 1:21: How the faithful city has become a whore, she who was full of justice! Righteousness lodged in her, but now murderers.
And Jeremiah 5:1: Run to and fro through the streets of Jerusalem, look and take note! Search her squares to see if you can find a man, one who does justice and seeks truth, that I may pardon her.
10 Day and night they go around it on its walls, and iniquity and trouble are within it;