Bit lacking in context.
It could mean : "I come [?came] across [town ] the wrong way, but normally I come the right way" = this time of coming across town I took the wrong route.
I come across [in behaviour/speech] the wrong way, but normally I come [across in] the right way. - I was talking to someone and it all came out wrong so they were offended. However, if this is right, then it is awkward and not well expressed.
Perhaps you can give more information about its context.