Shabbos 16:8-17:1

Shabbos 16:8

If a non-Jew lights a lamp on Shabbos, a Jew may use the light; if the non-Jew lit it for the Jew, then it is prohibited. If a non-Jew filled a vessel to water his animals, a Jew may also water his animals from that vessel, after the non-Jew; if the non-Jew filled the vessel for the Jew, then it is prohibited. If a non-Jew places a ramp to disembark from a ship on Shabbos, a Jew may use it to disembark after him; if the non-Jew made the ramp for the Jew, then it is prohibited. It once occurred that Rabban Gamliel and the Elders arrived on a ship on Shabbos and a non-Jew assembled a ramp for them to disembark, and they did.

Shabbos 17:1

Pieces of furniture may be moved on Shabbos with their doors, even if the doors became detached on Shabbos. This is because these doors are not like the doors of a house, which are not designed to be moved.