Malevolent Spirit: Malevolent spirits are swarms of barely visible machines that have accidentally been imprinted with a deceased person's memories. They posess swarm intelligence and communicate with each other through acoustic vibrations. They also share their energy through electromagnetic induction. The power source on this scale is usually the Sun and the alterating magnetic fields of electronic devices.
These "spirits" are capable of moving around small items (shoes, your collector's edition games, basically anything a cat can) at normal speed, larger objects at a slower pace. An ordinary wooden chair has to be moved for several hours to reach the other end of a room. These swarms are also capable of inducing hallucinations, supressing the immune system, and creating small wounds.
Typical ghost stories and creepypastas feature incense burners as a way to get rid of malicious entities (though tax collectors are too powerful for them). I wonder how could a regular incense burner effectively hamper these "scientific" spirits' aility to do harm?
I see you're getting creative with the answers, so we're gonna employ Occam's Razor: The simplest is the best.