Kinetic art help... Answered

Hi! Longtime lurker,1st time poster. I am wanting to make a kinetic work that kinda resembles ghosts... fabric that moves similar to this but more covered like it's someone with a sheet over themselves...



I have bought nitinol (.15" gauge), burnt my fingers applying electricity directly (LOL) and thought I'd try a mechanism to pop up similar to a jack in the box or whack a mole, or a cam and follower. I really love the NiTi but I am open to any suggestions from any resourceful peeps here. I am gonna go shopping for toys to open up sometime this week for ideas but in the meantime...
The main features I want are:
random activation, pop up go back to original position, inexpensive...
Thank you in advance for ANY insight, ideas. Much appreciated. Yours truly, The Lurk