Most ex-muslims I've heard of tend to avoid Abrahamic religions as Qtian wrote, but a few of them become Christian.
Which in my head does not really make any sense.
It might be for the sense of community and for a persistent belief in a higher power. I know some really nice churches here do a lot for their larger communities, needy individuals, and their congregation. If you have been cast out and shunned, it might be that a new community is your first impulse.