During the day, Halloween masks look pretty cheesy. Hanging from the drugstore rack’s seasonal aisle under the terrible clarity of fluorescents and the afternoon sun, it’s hard to image these killer clowns and fat-cheeked Frankensteins frightening anyone. Their warped faces and weeping pustules, yellowed horns and sharpened teeth, all a static, cartoonish fakeness crinkling in the soft latex. But they do frighten, only in the right place. Or better yet, they let fright happen. Night shadows make those masks less costume and more possibility, the cheap details worn away with the darkness. The contrivances of Halloween allow for the playacting of fear and violence, a space and costume to exorcise one’s inner demons by becoming them. And besides all that, the freaks come out at night. Who makes a monster? The feared, the outcast, the othered. Most of us find easier affinity with the monsters than with the pitchforked mob that sometimes chases them. In the darkened gallery at Gavlak, Marnie Weber gathers a coterie of monsters with stacked Halloween masks under a weeping willow dangling shards of stained glass. Along the walls hang a suite of pagan collages and through a dark doorway church pews face a screening of the artist’s first …