所 and 戶 don't sound similar in modern Mandarin due to historical phonetic changes. They were more similar in older Chinese.所 /*s-qʰ<r>aʔ/, /*qʰaʔ/ 戶 /*m-qˤaʔ/, /*m-qˤaʔ/
place, location; numerary adjunct; actually; place; classifier for houses, small buildings, institutions etc; that which; particle introducing a relative clause or passive; CL:個|个[gè]