Yes it can be normal to have continuity to earth from some things that are connected on the live side, eg a bulb with no live supply will transmit a earth all the way from the earth on bulbholder through filament up the wire to the first break in circuit, usually switch, left any switch in the on position ?, but some stray earth will always be found lots of things "leak" electric, I assume from this you are using a digital multimetre ?, as there is so little needed current wise to show earth it shows up.
The usual one to catch people out is the door being open, this will "join" the live and earth(negative) through the bulbholder!!
tabetha