in reply to Transferring local hashes to module subroutines

If you had run the code you posted, strict would have given you a strong hint as to what the problem is:

Global symbol "$hash_to_send" requires explicit package name at - line 11

You're fortunate that it's easy to see the problem from the example code you gave, but we'll have an easier time answering your questions in the future if you post your actual code verbatim.