You might see this sign by a light switch. The first word is handy as it means "do not". In Thai it says "yaa leum bit fai" which translates as "don't forget to turn off light". Actually "bit" also means "close" which is why a Thai will say "close the light" in English.

อย่า ลืม ปิด ไฟ (yaa leum bpit fai)