The moment one enters Eric Cameron’s installation, “The Divine Comedy,” the space is plunged into darkness. After a minute of tape-recorded laughter, a slide projector’s flashing strobe and intermittent glimpses of ghosts in museum vitrines, the lights come on. Though Cameron advises his audience to attend to the material reality of the sculptures, his wraithlike white shapes look more like manifestations at a séance than the result of the mind-numbing project he initiated a decade ago. Cameron applies thousands of half-coats of acrylic gesso to ordinary objects in his apartment and the “thick