I agree, sounds like an M/X/V -- if so, X is for electronic flash, M for flash bulbs, and V is the self timer. If you don't have the M and V, M will usually be closest to the X, and most shutters (in my experience) won't go into V unless cocked. Probably best not to put it in V, however -- many older shutters will jam solid if put into self timer, and only a full CLA will put them right.
Danger! Danger!
Donald is right. If the selector is on X, leave it there.
Sounds like a prontor svs shutter. If it is the same camera I have, it is a coupled rangefinder folder. The lens is not front element focusing, the whole lens moves on a helical connected to the rangefinder. It is not easy to dismantle to cla, so don't try. My camera has the Scheider Radionar 80/2.9 lens. It gives excellent results when stopped down to f11 or f16. If your camera is in good condition, it is a keeper/user.