It's an old, old practice; mainly from Germany and Poland and Slovakia, places like that, and passed down. It faded out (along with so many other things) after Vatican II.
My niece married into a Polish family decades ago; her husband at the time is now deceased, but his grandmother kept a very strict, devout Polish Catholic household. I was only in her house once, but there were shrines and statues and candles everywhere. The one TV was an ancient Philco that didn't look as if it had been turned in several years, and there were no radios. Every room in the house had a crucifix and a picture of Mary, and every bed in the house also had a crucifix attached to the bed frame. It was interesting and inspiring, but it was also kind of weird, in a way, LOL.