Please ensure (that) all lights are switched off.

请务必将所有灯都关掉。

《牛津词典》

Turn it off, please.

请关掉它吧。

youdao

Please switch the lights off as you leave.

你离开的时候请把灯关了。

《牛津词典》

Please. It makes noise when you turn it off?

关机的时候会发出声音？

麻省理工公开课 - 固态化学导论课程节选

In the summer months, there are 10 trains per day in each direction, so it is easy to hop on and off as you please.

BBC: Corsica, by breathtaking and bumpy train

Here's my humble plea: MY FELLOW RIDERS, PLEASE TAKE OFF THE EARBUDS AND HEADPHONES!!

WSJ: Jason Gay: Cyclists, Can You Hear Me Now?

Would the last one to leave the island please turn off the lights?

ECONOMIST: The state of France