Wiktionary
mighta
vb. (context colloquial English) (eye dialect of might've nodot=11 English), might have.
Usage examples of "mighta".
Even if he had not given the game any credence, he mightas Odille had suggestedhave said the exact same thing in order to gain a hold on me.
You might say him and me is tighter*n ticks," Jill agreed happily, "though no one what beared us talkin' on the way east mighta guessed it.
She mighta slummed, Alex, but I don’t see her getting anywhere near a burnout like Kristof.
Got summat fer yeh here — I mighta sat on it at some point, but it’ll taste all right.