Here’s what I could find: 
After getting exercised by variant universal energy or something like that, the ghost in question sought a new host body amidst Central City. He initially inhabited a Beebo doll, but Beebo’s inherent goodness left the ghost in a weakened state. To recuperate, he required another host body, so he found a doll from the public domain to inhabit. It just so happens that my sister Yera bought said doll for my prospective niece. (She likes The Flash, so it all works out.)
When the doll started talking to her (“Find me a new host”, “I need to feed”, “This attack was no accident”, etc.), rather than telling me or a verified intergalactic enforcement agency (She never tells me these things.), she characteristically and irresponsibly assumed everything was fine and ignored it. The doll told my niece to go to an abandoned house in my old cul-de-sac (one of those ominous houses that’s only noticed around October 31st) where she gave it to me because, at this point, she grew out of the talking doll fad and moved toward videogames. When she left, (It was about dusk.) the doors shut, and now, the ghost is waiting for the “Multi-Cube”`s energy to die out so he can use me as a host body.
Four hours and 41 minutes to go…