"Might" is very similar to "podría" in Spanish. Most often we use "might" to indicate we are not certain. to make a very polite request, or as the past of "may" when used for requests.
I might go the the movies tonight (pero no estoy seguro, es una posibilidad).
It might rain tomorrow (posibilidad de lluvia).
Might I borrow your newspaper? (very polite and a bit formal).
He asked if he might borrow my car.