No, neither do I, so you must understand why I find your assertion that some wizards obtain their magic this way puzzling.
Unless you are talking about grown muggles trying to steal magic, but they'd need magic beforehand to contain the entity, so any muggle trying to summon one would die.
[Private]
I am writing this part privately because I do not wish to distress any ladies who may be reading.
My brother tried a summoning, once. It didn't work, but I got in trouble just for watching. Our father said that if it had worked we'd both be dead, and that he'd once heard of a creature from another realm tearing out a wizard's guts and eyeballs for no reason at all. Apparently it made the Auror who found the body retch, and they're supposed to be tough. A muggle wouldn't stand a chance with demons.