dual network for single machine, possible bridge

[Dave Ng]

I have two networks at home, there are some wifi shenanigans going on
but for the point of this conversation I only mention the wired
ethernet. Two hub/switch setups, 192.168.1.x and 192.168.2.x, they are
separate and they work great and life is good.
I am adding a single freebsd host with two NICs in it, one on each
network. No complications, right? Set the IP addresses manually and I
can participate in each network, using a single gateway off one of
them to reach the outside world. I think?
Next question, can I use this host to bridge the two networks?
Next next, assuming I can bridge, is there any way to do so
transparently for other hosts on either network? They are a mix of
OSX, windows, blah blah every OS.
Thanks!
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