屋 and 室.
They both have the same phonetic part, 至, but yet are pronounced nothing alike, and not like 至 either. [shì and zhì are spelled quite similarly to each other in pinyin, but to me they sound nothing alike..... the dangers of pinyin!]
They have more-or-less the same meaning, but their usage is different and often can't be interchanged.
They have different radicals, and 尸 is very weird here, I assume it used to be 戶, which would mean the radials are similar.
I just can't tell them apart.