戊、戌、戎、戍

Here are some characters that look alike.

戊 wù/mou6 '5th of the 10 Heavenly Stems'. Used as phonetic in 茂 mào/mau6 'luxuriant; profuse'

戌 xū/seot1 '11th of the 12 Earthly Branches'.

戎 róng/jung4 'weapons; military affairs'. Used as phonetic in 絨 'down, velvet'. Interestingly, 'thief' 賊 zéi/caak6 looks like it has this as a component, but the original character had phonetic 則 zé/zak and the weapon radical 戈 gē/gwo1. According to Wenlin, there's an obsolete form 𧵪.

戍 shù/syu3 'defend; garrison'.