睪 (gāo) is the Taiwan/traditional spelling for 睾 (gāo, 'testicle'). On the mainland the lower variant 睾 is standard, so 睪丸 vs. 睾丸 is the same word in different scripts. Don't confuse with the very rare archaic reading 睪 (yì), 'to spy out from a height', found only in classical texts.
mistakes
The character looks similar to 皋 (gāo, 'high ground / shore') and 睾 - three near-identical glyphs. The 'testicle' meaning is always written 睾 (mainland) or 睪 (Taiwan); 皋 is a totally different character meaning 'marshland edge'.
罒 is the flattened-top form of 目 (eye) and carries the "watching" sense - 睪 read yì originally meant to spy on or inspect from a height. The eye-on-top motif also appears in 罗、罢、置.
幸 here is not "lucky" - it stands in for an old shackle/handcuff graph showing a captive being watched. The modern shape was assimilated to 幸 over centuries. In the anatomical reading, the eye-over-shackle visual is purely accidental.
Filed under radical 目 (mù, #109) by convention. 目 is not a separate component in 睪, so no strokes are highlighted.
