They might would do it.

source: 
LAGS
Entry: 
569
Example: 
They might would do it.
Modal 1: 
might
Modal 2: 
would
Gender: 
Male
Race/Ethnicity: 
White
Age: 
82
Level of Education: 
4th grade
Home Community, Town, or State: 
AR (Piggott)
Location Collected: 
AR (Piggott)
Year: 
1974
Relation to Addressee: 
subject to fieldworker
Medium: 
Spoken
Sentence Structure: 
1.0
Status: 
Naturalistic