Goosebumps: Bride of the Living Dummy(1998)

It's a match made in horror.

A ventriloquist named Jimmy O' James finds Slappy's ventriloquist case and accidentally summons Slappy, and now only two teens Jillian, Harrison and Jillian's sister, Katie can stop him but now Slappy is in love with Mary Ellen, Katie's doll and will stop at nothing to get what he wants.