The Mad Scientist is at it again. He’s got instruments and electricity, leather gloves and big thick goggles.And for the last 20 years, Rick Feuerstein has the chance to showcase his love of Halloween and his longtime passion for the old-school “Fright Night” style scares of his childhood. Tonight from 6 to 9 p.m. Feuerstein will welcome all takers to his home at 1373 Pajaro Avenue – just around the corner from Neil Hafley Elementary School – as he showcases two decades worth of collecting in an elaborately staged laboratory scene that would have made Victor Frankenstein jealous.