Star, go carefully. This is not a game. You have a sociopathic colleague. I speak form experience. And if your co-worker has confirmed tat this has happened before, then this idiot has form.
Now, sociopaths in the workplace are not uncommon. Also, mostsociopaths are law-abiding, if only because they don't want te inconvenience of going to jail for anything. But tey DO brak social rules if they feel it is to their advantage to do so. They are cannyenough, careful enough, to make the system work for them personally.
When he tells you he is working as a manager - call in te boss, in front of this bloke, and ask the boss to please confirm who is manager. But if there is the faintestchance that your boss is beleiving the rubbish the sociopath is spreading, then don't do it in front of him, go to the boss privately and say, "I wish to clarify some things." Also point out to the boss (if osmething like that alleged hour-long conversation comes up) exactly what you told us. First, it was half an hour. Second, you were still getting work done plus you don't do this as a regular thing and you DO put in extra time for any time off you take. And until now, you hve not been in the habit of 'dobbing in' othr workers because you have felt the boss has better things to do, as long as the office is running sufficiently smoothyl. But you are concerned at the vibe you're getting form this bloke, you have caught him listening at doors and going through your stuff when he should have been focussing on getting his own job done. If he has the time to spare to snoop, then perhaps he needs some more things to occupy him?
Set small traps by all means, but don't make your discovery of them obvious. Don't leave rude notes with any obscene words, he will find a way to use it against you He will accuse YOU of wasting office time in petty mind games and paranoia.
Of course, tat doesn't mean you can't set up something that with hindsight, does not look like a trap but functions like one. By all means confirm privately to yourself with the stickytape test, if he is snooping. Then find some otherwise innoccuous chemical which is freely and legally available, but which stains your fingers indelibly. I'm thinking, potassium permanganate. husband will advise when he checks this link, or I'll ask him. Put some in a paper envelope in your drawer, do not seal the envelope (I don't think) but if it's one of those envelopes which you close with a piece of string wound around buttons - that sort of seal will be good. But nothing sticky or that needs slicing open. Put some paper in there too, with writing on it. Anything innocuous, perhaps the manufacturer's data on the chemical. Then leave it in your drawer. Mark the envelope with something truthful but tempting, such as "Private and personal."
And make sure you have a valid reason for having potassium permanganate in the drawer. Perhaps a small amount you bought for a school project for Dude...
And do make sure that you don't have any really important papers in the drawer as well. or perhaps make sure you DO (but have a private stash of clean copies) because that powder stains purple when it gets damp, say on sweaty fingers...
And elsewhere, make sure you have a bottle of 2% hydrogen peroxide, it's brilliant for getting that purple stain off your skin...
Hopefully husband will check the accuracy of this for me, he may even have better ideas.
In the meantime, keep on being a decent, upstanding citizen in the workplace. And take the boss quietly into your confidence, especially AFTER the purple skin thing, if it works. Take photos if you can. If you can get a photo of him snooping by your desk - great!
But go easy. This isn't high school silly games. A sociopath in the workplce can do a lot of damage to a business, purely in their own zeal to get promoted way above their own personal capability. They will tell bigger and bigger lies in their attempts to cover their tracks and having no conscience, will not hesitate to shaft anyone who gets in their way professionally or personally. I even had such a person spike my drinks at office parties, and had some hash brownies given to me (without telling me what they were) for afternoon tea one day. I had stayed in to work, while the others went out to lunch with the sociopath. They all came back late and I think sociopath was angry because the boss had sprung them all sneaking back from lunch at 4 pm. Sociopath blamed me and slipped me the bikkies. Thankfully, the boss never knew. I had the weekend Occupational Therapist (OT) recover, but I did have to drive hom throuh peak hour trafficc, with three kids in the car, knowing I was "under the influence" and dodging telegraph poles that kept leaning over trying to tangle my car as I drove past...
Go carefully, Star.
Marg