В темноте я нашёл выключатель в прихожей и включил свет.

In the dark I found the light switch in the entryway and turned on the light.

Breakdown of В темноте я нашёл выключатель в прихожей и включил свет.

• я: I
• в: in
• и: and
• найти: to find

Questions & Answers about В темноте я нашёл выключатель в прихожей и включил свет.

Why does Russian use в темноте here? What case is темноте?

В темноте means in the dark / in darkness and uses в + prepositional case to express location/setting.

• Dictionary form: темнота (darkness)
• Prepositional singular: (в) темноте
  So it’s literally in (the state of) darkness, not “in a dark (room)”—it describes the conditions.

Why is it нашёл and not находил?

Нашёл is perfective past, meaning a completed, successful result: I found (and now I had it / located it).
Находил (imperfective) would usually mean something like used to find, was finding, or focus on the process without emphasizing the result—less natural for “I found the switch (at last)”.

What’s going on with the spelling нашёл vs нашел?

Both refer to the same word, but:

• нашёл (with ё) is the accurate spelling and shows the stress: na-SHOL
• нашел (with е) is a very common informal/typographic replacement when ё isn’t used
  In learning materials, ё is often kept to help pronunciation.