I want to run Cat 5 cable along the side of my home in 1/2 in. EMT Conduit. I was considering actually pulling to Cat 5 cable in that conduit. Will this cause any problems on a 100Mbps connection between a video camera and my GB switch?
As long as you're not running power in the same conduit or parallel to the conduit within about a foot you will be fine.
Rob has already addressed the safety issue: don’t run low voltage and main wires in the same conduit.
But I think you are asking from a noise and bandwidth point of view.
Noise The EMT can act as an antenna. To avoid any interference take care to bond it to equipment ground at both ends.
Bandwidth Cat5 cable is rather out of date. I would never use less than Cat5e and probably your cost to go with Cat6 is minimal. If there is any chance down the road you plug a switch in where the camera is to wire up several cameras then you will prefer to have used better cable. Unshielded twisted pair (UTP) is fine. Shielded is nice but more expensive and if you are putting this in a grounded conduit by itself then not much point.