You can put some redstone component blocks over fences and walls.

Yup this might be a bug. Nowhere in the official Minecraft Wiki did I find that Redstone and Redstone related blocks, or doors can be placed on dust, levers, buttons, repeaters, comparators, doors and rails over fences.

No please keep it its really cool and gives weird to the fense 🙂

While this is a pretty goofy bug for most redstone components, I actually like buttons being able to be placed on fences because they give them a neat look. (See the attached screenshot I added.) Perhaps an exception could be made for buttons, just because it actually kind of makes sense and looks cool? (unlike the redstone dust and other components which kind of look like they're floating.)

Please note, the wiki is just a wiki; it is NOT an official documentation source.

I wish I could place such things on fences in normal MC...

Confirmed for 0.15.7. (Tested on Windows 10.)

Affects 0.16.0 Beta Build 4 (AKA 0.15.90.7).

This issue should be renamed to reflect the fact that doors, rails, and redstone dust can no longer be placed on fences/walls. I suggest this new name:

"Buttons, levers, repeaters, & comparators can be placed on fences/walls"

Added a new screenshot clearly showing the affected blocks in 0.15.90.7.

Affects 0.15.90.8 (0.16.0 beta build 5).

Fixed for doors, redstone dust and rails. The other items are supposed to be able to be placed on fences.