A Type M plug in Guam?
Not directly — pack an adapter.
Guam's Type A / Type B sockets don't take a Type M plug. A plug adapter solves the shape problem — it changes pins, not electricity. The wall delivers 110 V at 60 Hz (99–121 V within tolerance) — if your device isn't rated for that (look for "100–240 V" on the brick), an adapter won't save it.
Grid facts verified against IEC World Plugs — Guam. Physical-fit verdicts derive from pin geometry and each socket standard's acceptance list — not safety advice.