Is ghusl necessary after drops are emitted from the penis during a state between wakefulness and sleep, given a history of urinary incontinence?

The drops the questioner finds are considered urine. What came to his mind about them being semen is a baseless whisper (waswasah). The characteristics of semen are well-known and distinguish it from other fluids. These include: discharge with desire, followed by a sensation of relaxation; a smell resembling pollen; and discharge in spurts and gushes. Each of these characteristics is sufficient to establish that it is semen. Based on this, the questioner was not required to perform ghusl (ritual bath) for janabah (state of ritual impurity requiring ghusl), and he should disregard these whispers.