A centering guide cage apparatus for interior wall drilling includes a drill-bit holder, a flange bearing, a centering guide cage, a flexible casing, a hand-grip turnbuckle, and a flexible drill shaft. The centering guide cage, equipped with plurality of shape-memory supports, is terminally connected to an outer race of the flange bearing. The centering guide cage is terminally connected a distal end of the flexible casing from the opposite end. The hand-grip turnbuckle is terminally pressed against a proximal end of the flexible casing. A distal end of the flexible drill shaft is terminally connected to the drill-bit holder as the flexible drill shaft traverses through the flange bearing, the centering guide cage, the flexible casing, and the hand-grip turnbuckle. The flexible drill shaft is radially connected within an inner race of the flange bearing, wherein a proximal end of the flexible drill shaft is engaged with a drill driver.