Is mohini pisasu same as succubi?

The succubus is a demon who is sent during sleep (mainly) to tempt a man to have sex to corrupt him as well as to collect his sperm to create monsters through the incubus impregnating women.

The Hindu religion doesn't have a concept of Hell (with a chief in charge - Satan , who can tempt folks for their souls) and therefore the mohini is different from the Succubus.

The mohini is a spirit who has not yet moved on from this world and doesn't have a physical body (whereas the succubus can take on a physical shape).

Most likely both are cases of sleep walking and other sleep disorders combined with maybe drug usage in the olden days :)