For convenient characterization of the roughness of the interface between two different piezoelectric/piezomagnetic materials (PPMs), a wavy contact model is developed. Eight potential functions are proposed, which makes the considered mixed boundary values problems mathematically tractable. Important physical objectives, such as the unknown contact region and surface normal stress, are presented explicitly. Results in a special case, full contact, are offered. Figures are plotted to show the effects of the piezoelectric phase volume fraction and the external loading on the interactions between two different PPMs. Numerical test reveals that enhancing the piezoelectric phase volume fraction produces a wider contact region.