[Grammar] ‘obsessed with’ VS ‘obsessed by’

[northpath]

Here are two sentences:
Tom is obsessed with football.
A lot of young girls are obsessed by their wight.

Why the preposition ‘with’ is used in the first sentence and the preposition ‘by’ in the second one? Can I swap them?

 

[bhaisahab]

I wouldn't use 'by' in either of them.

 

[Rover_KE]

obsessed with is more common. [link]

 

[GoesStation]

Why is the preposition ‘with’ [STRIKE]is[/STRIKE] used in the first sentence and the preposition ‘by’ in the second one?

Please study how to form questions in English.