戊、戌、戎、戍
Here are some characters that look alike.
戊 wù/mou6 ‘5th of the 10 Heavenly Stems’. Originally a picture of an axe-like weapon. Used as phonetic in 茂 mào/mau6 ‘luxuriant; profuse’.
戌 xū/seot1 ‘11th of the 12 Earthly Branches’. Originally a picture of a type of battle axe.
戎 róng/jung4 ‘weapons; military affairs’. Originally composed of a shield (the 十 part) and a lance-like weapon 戈. Used as phonetic in 絨 ‘down, velvet’. Interestingly, ‘thief’ 賊 zéi/caak6 looks like it has 戎 as a component, i.e., 貝 + 戎, but the original character was actually 則 + 戈, i.e., 則 zé/zak as a phonetic and weapon 戈 gē/gwo1 as the semantic. According to Wenlin, there’s an obsolete form with a 刀 instead of the 十.
戍 shù/syu3 ‘defend; garrison’. Originally 人 + 戈.