I might can do that.

source: 
LAGS
Entry: 
299
Example: 
I might can do that
Modal 1: 
might
Modal 2: 
can
Gender: 
Male
Race/Ethnicity: 
White
Age: 
86
Level of Education: 
Elementary school (Some)
Home Community, Town, or State: 
GA (Chatsworth)
Location Collected: 
GA (Chatsworth)
Year: 
1968
Relation to Addressee: 
subject to fieldworker
Medium: 
Spoken
Sentence Structure: 
1.0
Status: 
Naturalistic