A cultural feature of Genoa and cities in the south of Italy, and many other places in the Mediterranean, are the small shrines or ‘edicole sacre‘ that are literally everywhere. In Naples they are often found on street corners and on the sides of buildings, most especially in the Spanish Quarter.
The practice of building small altars in public spaces in Naples probably began with the Greeks and was taken up and spread further by Christianity.
A teacher that I worked with once told me that during the reign of Charles III of Bourbon (mid 18th century), his adviser Father Rocco, with a view to reducing street crime, encouraged the spread of the shrines and the lighting of candles inside them.
This created the first system of street lighting which allowed the local population to walk around at night more safely than before.
Electric lighting has replaced the candles now of course.
Other names for edicole sacre are capitelli, nicchie votive, madonnelle, madonnine, santelle, tabernacoli and votivi.