I know at least two houses where there are numbers of these stuck in the roof inside.
The custom of putting them up is dead but the crosses still remain. Some of them are about one foot in height and all are partly ‘x’ shaped thus:- ( diagram ) . One man told me he remembers having seen them put up on St. Patrick’s Eve. They were not used as a charm or cure of any kind but to use his own words “ they were put up in the memory of the faith brought by
Patrick “. In a couple of samples I found no nail but a timber peg driven right through which acts as a holdfast by which the cross is affixed to the roof. I have seen one house where there are several of these crosses and side by side with them several samples of Tadhg a Gheimhridh.